I've been playing a bit of Oblivion the past few weeks. While it's a real bear to get running at anything approaching decent resolution (1280x720 is still a bit choppy, even on a SLI GeForce 7950 rig), it's very involving.

Oblivion Domino Day - Hopefully someone did this with the CE (Construction Editor) and not in-game, because it's nigh impossible to place books accurately in-game. The NPC that they're killing is the "Adoring Fan". Reportedly one of the most annoying NPCs in the game.

Oblivion Domino Day II - Same thing, different setup.

Oblivion Fun - First a dive off of "Dive Rock". Followed by lots of jumping and getting outside the walls of Imperial City.

Oblivion Fun - A continuation of the above. More fun with "Dive Rock". Followed on by fun with spells.

Oblivion Fun - More fun with Havoc physics. Features Cloud Ruler Temple.

A Brush With Death - Shows the entirety of the "A Brush With Death" quest, which is one of the wildest landscapes (even though it's imaginary).

The Elder Scrolls IV: Oblivion - Gameplay Footage

Elder Scrolls IV: Oblivion Review

The Elder Scrolls IV: Oblivion Review

Elder Scrolls IV: Knights of the Nine - Review

On the whole, Oblivion scores about a 80/100. Once you heavily mod it, it makes a lot more sense and plays better. But you'll still have to deal with semi-frequent crashes, video glitches, and a AI that isn't always the smartest. Once the GeForce 8800/8900 cards get down around $100, plan on setting up a SLI rig and giving this a play. Until then, you're going to have issues with framerates.

Specifically, you should install Obsuro's Overhaul for a better gameplay.