Mafia II - I didn't think much/anything of it. I could never recommend it.
Metro 2033 - Kind of short and really has no replay value. I really didn't care for it.
Red Dead Redemption - PS3 & Xbox360 only
Red Dead Redemption: Undead Nightmare - PS3 & Xbox360 only
Need For Speed: Hot Pursuit - Pass. There is virtually no vehicle modding and free roam is completely pointless. I'd rather buy Test Drive Unlimited (2) than that.
Braid - So-so. The story is impossible to follow but the gameplay is rather interesting. It should also be pretty cheap (I got it in the Humble Indie Bundle).
Two Worlds II is pretty fun but it has little/no replay value. It is most similar to Oblivion in gameplay but it isn't as polished/large/deep. If you liked Oblivion and can get TW2 for cheap, go for it.
Assassins Creed: The first one is completely skipable. The plot was impossible to follow. All you need to know from that game is you played as Altiar and he killed a templer that got hold of an apple. AC2 is the best of the three. ACB is decent. ACB won't be easy to follow without first placing AC2.
Prototype, maybe? Oh, and Hitman Contracts isn't in your list. I liked it a lot. Blood Money is better but only slightly.
I liked The Saboteur. Beat it two or three times. It's about the only WWII centric game I like besides Company of Heroes.
Splinter Cell Convinction really has nothing to do with the games before it except proving that Sam Fisher is a grade-A badass. Little/none of the plot carries over besides some characters which are adequately explained. On second thought, you should probably play Double Agent first. It explains why Fisher is on the run in Conviction. Splinter Cell, Pandora Tomorrow, and Chaos Theory are pretty good games but they aren't required to follow what is going on in Double Agent (except establishing that statement above: Fisher is a badass). The Splinter Cell games require a relatively new graphics card or they won't work/play well.
Fable III is a non-crappy Fable II--at least from what I've heard about Fable II. They're effectively the same thing but Fable III is better executed.
Braid I bought the retail release of last Tuesday. Only a CD-ROM but it's fine.
For the sequels I think it'd be best for me to complete them before playing the next entry. I'm a bit of a stickler when it comes to that.
For METRO 2033 I'll buy it for PC but wait until the computer I'm building is finished and install AFTER I have the 6950 2GB flashed to 6970. Shadow of Chernobyl plays quite alright on my current rig, planning to buy the other two and same thing with METRO 2033. Waiting until PC is fully finished.
Oh I'm fully intending to own all the HITMAN games and attempting to go for the Silent Assasin thing for each mission. No running and gunning in it.
Already have the entire GTA series in my Amazon.com wishlist, will be able to play Original and III-series but going to have to wait for IV and Episodes from Liberty City with completely finished PC. Could purchase all now, download tons of mods for all of them and still wait to install the last two when PC is completely finished. Going to use ENB mod for IV/Episodes from Liberty City.
Console exclusives are fine anyway. Games released for console with a PC counterpart most likely will be buying/playing demo of console version first then eventually getting it for PC. Or just playing games at friends houses.
HAWX demo from Steam was fine and was able to play it alright. For $7, why the hell not? Many games I can barely play on my current POS pre-built will have far superior settings capabilities when built PC is completely finished. Gonna aggravate me having all these games and waiting for the PC to be done to fully play them without extremely sluggish framerates.
I can barely play Oblivion right now when a couple months ago it played alright. I hate my current POS pre-built tower and NEVER AGAIN! Still just a few more months and I'll be able to play any current game released in the past few years with the setting as top as I'd like.
Well it's nice for the Games for Windows/Live titles since I already own a PC 360 controller but some others it'd be nice to have XPadder for them.
DEAD RISING 2. Buy it for PC or 360?
Loved DEAD RISING.
EDIT: I'm glad demos are available but my current POS can't even run half of them, except HAWX.