It's a laptop. Only the high-end ones have options to upgrade video.

If you're gonna use Dx8, you should get Hostile Waters: Antaeus Rising (it seems to choke on Dx9). At $2-$5, it's quite a steal. Obviously Morrowind, Deus-Ex, Original HL.

You could find a copy of Doom95 and tell people you run Doom on your machine (of course they will assume you mean 3, but they'd be wrong), as long as you can stand it's amazing (compared to the DOS version) 640x400 resolution. Doom is still a great game for mindless killing, but Serious Sam looks much more spectacular while accomplishing the same purpose.