OK, as long as we are putting our thoughts into the newest generation consoles. The most important reasons for me choosing a console are the potential software and the price.
Price: currently the 360 is a good price for buying one, but at it's launch the price was too high. The price of the 360 was also too high at the moment of the launch of the Wii. PS3 is still too high. I ain't going to pay €399,- for a freaking PS3 with 60GB HD and Little Big Planet. No matter what high end hardware or special features it has. After a year it is outdated anyway.
Potential Games: I always look at the games coming with the launch (and a few months after) and also the potential of future games. Agreed Nintendo has an unfair advantage because it has a long and rich history of good franchises. Microsoft is still a relative newcomer. Sony also has a number of good franchises, which until this moment have remained exclusive for the Playstation, but the most of them are 3rd party and could change consoles at any given moment. At the launch of the Wii I had a number of games I wanted to play. At the launch of the 360 there was only 1 (Kameo) and at the launch of the PS3 there were none.
And at this moment I still find the Wii to have a more appealing lineup then the others. What can I say I just like games which are totally unrealistic and brightly colored. For me games are about the fun factor and that is what Nintendo is still good at. With the 360 and PS3 I get the feeling they are all about realistic looking graphics and a lot of blood and gore. I just don't like that very much. i also get the impression that the PS3 and 360 is more into the horror and fps games, and that are two genres I don't like (with the exception of Goldeneye on the N64).
I don't know if it is true anymore, but I've often heard the argument that the 360 or PS3 have more games in their lineup then the Wii (not counting backwards compatibility). But frankly I don't have the time nor the money to play and buy all the games I like on the Wii, so that is not so much an issue. (On a second note, I rather like that not so many good games are released at the moment for the Wii, because it allows me to catch up.)
Backwards Compatibility: seemingly important to some people, of little importance to me. Why you might say. Well for all of the older generation games I still have, I got the required console as well. And the older generation games are hard to get. Although with Nintendo's newest cash-in action of 'New Play Control', it is easier for some. Additionally like in the previous paragraph, I don't have the time nor money to play them (all).
High end Graphics and Audio: Another feature which doesn't bother me all to much. I could see the difference between NES and SNES, SNES and N64 and N64 and Gamecube, but after that it all became the same to me. I couldn't notice any difference in graphics between PS2, Gamecube and Xbox, nor can I see any difference between the previous generation consoles and the current. I instantly believe the numbers you will throw at me about polygons and pixels and the improvement of HDMI. But frankly when I'm playing a game it isn't different to me. Maybe because I'm to focused on the gameplay or I just don't have an eye for these aspects. Or maybe it is because I subconsciously just don't care. The same goes for the audio BTW. I still love the good old SNES graphics, but that may be nostalgia speaking.
On line: I actually hate the trend that multiplayer has to go on line. It becomes impersonal and distant. I know about voice chat and all that, but it still doesn't replace the entire on the couch sitting an looking with a number of people at a (split) screen. I noticed this with LANning as well. Even though we are sitting around the same table, all the social interaction is gone. If I want to sit alone in a room playing a game, I rather do it in singleplayer mode, than against a faceless opponent across the world. In multiplayer I want to be able to look my opponents in the eye, curse them, give them nudges with the elbow or knees to distract them. Or making them pay attention to my avatar instead of their own. Really on line multiplayer? I rather play a silent game of cards around the table, then play on line with voice chat.
Webbrowsing? Helloooooo! PC anyone! Really to browse on line I would use a PC. A keyboard and mouse are a lot more usefull too. I know you can connect a keyboard to the consoles, but why buy/connect a keyboard to your console, when 99.99999% of the people have a (outdated) PC anyways. On a HDTV it might look reasonable, but on those TV's a webbrowser looks really horrible.
Downloading patches? In my oppinion, if a developer has to bring out patches to fix problems or add some features. I just think it is sloppy work. For the system it self I can live with it and I can understand that PC games require it, because due to so many hardware, it is practically impossible to test every configuration. But a console game. Helloooo! Couldn't the developer be bothered to complete the game before shipping it and selling it to customers. If I need to download a new feature,because they didn't include it in the sold version of the game, then that feature has to be one hell of a feature. In these cases the new features warrants a sequel and a complete new game is made. If I need to download a patch for a console game, because of a bug. Then that is just sloppy testing. It is only 1 configuration you need to test. But they just shipped an incomplete game, because a fart waited to long and wanted to see some money. This applies to Nintendo, Sony, Microsoft and all the other publishers and developers.
Game controllers: Let me start off with saying that I, unlike most, actually like the waggling of the wiimote and often prefer it over the button bashing on gamepads. I know people perform better with a normal gamepad, because they can react faster or are quicker of movement. But I can't help wondering if it isn't because we are trained in it and aren't used to the game immersion the Wiimote represents.
Wallnut: I don't know how you come to such a long list of peripherals, but you can play every Wii game with just 4 peripherals. The Wiimote, Nunchuck, Balance Board and Gamecube controller. All the other things are nothing more then decoration and absolutely not necessary. I have to admit that I also have a Wii Wheel and Wii Zapper, but that is because those pieces of plastic came with the games (Yes, I bought Link's crossbow training for the game and not the plastic). Maybe in the future the Wiimotion plus gets added to this list, but it all depends on its support in the games. One exception are the Instruments, but you have to buy those for the 360 and PS3 as well. And changing of controllers isn't that much of a problem, because I've stored them next to the Wii. The changing of controllers happens when I want to play another game and then I have to walk to my Wii to change the disk anyway. The only thing that takes more time is disconnecting the Nunchuck.
But back to the topic. I like the Wiimote, because of the waggling. With it I have more of an immersive experience. And the wiimote is actually the first step towards a gaming experience like Star Trek's holodeck. Although I might never experience that. There is nothing wrong with a regular gamepad, but it is less immersive. And the internal battery of the PS3 is actually a disadvantage because of several reasons. 1) You need a spare gamepad, for when the battery is empty, 2) (Don't know for sure), but you could play with a charge cable connected to the gamepad, robbing it of its wireless aspect. The cables probably aren't that long, which forces you to sit closer to the PS3. 3) When the battery goes dead, because of the many discharges and recharges, you need to buy a complete gamepad of €40,- instead of a new rechargeable battery of €2,- (maybe less).
I have probably forgotten a number of aspects, which I gladly give my oppinion on when asked. But for me the best console to buy was the Wii. Although I am considering to add another, but like I said. I don't have the time or the money to afford them.
PS: Many would ask what about the PC. Well in my oppinion it is a hell to game on my PC. I use it for business and study purposes and to play video (including Blu-Ray) and music. I really dislike playing games on the PC, because past experience has really soured it. To have a decent gaming experience, I was constantly tweaking the PC. I wasted more time and money on maintaining my PC for a decent gaming experience then I would actually be able to play a game. I hear people say that a PC has better graphics and more hardware strength, but that doesn't matter to me. And parts of the PC are very expensive and are outdated within a year. A console would last for a lot longer and isn't as expensive.
Secondly installing games is such a drag. When I buy a game, want to be able to put the disk in and be able to play it immediately, and not wait until the game has installed a number of GB's on plugins required for the game. Call me lazy, but I just don't like it.
Third the keyboard has to many buttons, that I always push the wrong ones. I know there are gamepads for the PC, but it is always praying that the one you have is supported.
Finally, because a PC has a lot of different combinations in hardware, it often happens that the game doesn't work in a certain combinations (even if you use popular parts). I had to wait for a patch which could take weeks and then all my interest in the game had vanished. For example: I've bought C&C Tiberian Sun, but never played it, due to a incompatibility with mouse drivers. Before that was resolved a few months had past and my interest was gone with the wind. Even today I still have the disk, but never played the game.
And that is why I think playing games on a PC stinks.