None of the above...
got a wii recently. playing zelda and some retro games on it now. wii sports and mario kart are fun, my gf likes to play them alot
I have a PS3. Its getting better now esp. since last year when they released a couple of big titles GTA3, MGS4, Dead Space, Fallout3, etc. Before that, I was quite disappointed with the system. Most games were shooters and ports from the PC (I'd use a PC if I wanted shooters ). Too few PS3 exclusives that made use of its game specific processor. In fact many Xbox360 games trashed PS3 or were equivalent in terms of graphics. All the WOW! games of old; FF, MGS, Jap strategy (eg. Front mission) were absent pre mid 2008. Pre mid 2008, I can only point to the very excellent (but short) Uncharted to be the finest example of a PS3 exclusive (story, graphics, gameplay, gameflow, in game animation).
However, if you like jap RPG/action games and strategy games, then PS3 is still the one to go for, and now is the right time, with so many past titles to get and tide you over till the good 2009 games come out.
If you like PC ports, online play, shooters, then Xbox360 is probably better. But then why not just use a PC
To TS, you mentioned some of the games you'd like to play... let me give a short review :
MGS4 - Good, but a disappointment for someone buying the PS3 for this game. Too much reliance on weapons. Too easy on weapons/ammo. No great push in graphics (ie. dead facials). Dated movement controls (just doesn't move/control as easily compared to newer games like uncharted, gears of war or assassins creed). Too long cut scenes, long winded and again complicated story (like MGS2).
Assassins Creed- Bad! I was so WoW!ed by the trailers. Turns out the gameplay is very repetitive (repeat to ad-nauseum). Bad, abrupt ending as well. Could have been much more of a game, but truned out to be a huge disappointment.