As a long-time Harmonix fan, I’ll opine that, regardless of whether you choose XB360 or PS3, Guitar Hero or Rock Band, just don’t - if you can help it - buy a Wii to play music games on. Not only do they generally have less features, with downloadable content (one of the main draws of these games) being a total pain requiring multiple workarounds, the structure of the Wii’s controllers mean that it’s the only next-gen system where the latest generation of GH-instruments and RB-instruments are completely incompatible.
What this means is that if you wanted to invest the ~$190 in, say, a Rock Band 2 bundle and get some playtime out of that, then wanted to try Guitar Hero: World Tour on a lark, you would have to buy a completely different set of instruments with which to play it. If you’re on 360 or PS3, however, the instruments, even drums, will work with each others’ game, and you’ll only need to spend $50-60 for the game disc itself.
The Wii is a great system to show off to people, but the 360 and PS3 have just as many casual titles, especially if you hit the downloadable stores with games like Uno, Peggle, Flower, and Banjo-Kazooie priced between $5 and $15.
Note that if you want to go over to your sister-in-law’s and play one of the newer games there because she doesn’t have it, you’ll have to have the same system as her in order to use your games and peripherals.
If you didn’t need more meaningless information to sort through, if you get the 360 and get Xbox Live, you can game with Dopers. Rock Band 2 is a popular game in the group.
On the Wii, Rock Band 2 is compatible with everything. The scenario you describe is true, in that World Tour doesn’t run on the Rock Band instruments. However, you can do it the other way, buying the full World Tour kit and just the RB2 disc.
I just purchased a ps3 a couple of weeks ago and took the GH plunge, i spent 400 on the ps3, 100 on world tour with guitar, and got rock band and GH 3 for 15 bucks each second hand, and i havent hooked it all up online yet, but the additional cost from the DLC i dont like much.
But it should be noted that you can get the games on PC also. Which i didnt know until i saw it on the shelve(after i bought it the day before. Does anyone have any information on the DLC for that? Wouldnt that be the best bet for the greatest number of songs overall? Since the newer games have the ability to do your own tracks surely in PC land there will be fans doing alot of work making the songs for the Pc version. Anyone know?