The Elder Scrolls IV: Oblivion for PS3.
I have to say, while it's not quite as addictive as Monster Hunter, which is probably in part to the online mode in MH, it's a great game so far. All of the weapons are armor look incredible, even on my SDTV. The only thing I really notice so far is the character look directly at you when speaking and don't convey much emotion, but that's obviously nothing game hindering, unless you're really picky.
The fact that you can customize all of your weapons, armor, clothing, and jewelery with a plethora of enchantments, as well as creating your own custom magic spells, just adds to the games replay value tremendously. I can't wait for all the download-able content to come out on PSN; I'm really looking forward to Frostcrag Spire and the Shivvering Isles expansion pack.