The current SiS integrated graphics (as found in AMD64 and recent P4 chipsets) aren't that bad. It's a fairly recent DX8.1 engine, and in the AMD64 version, the board makers _can_ give it up to 64 MBytes of dedicated (!) RAM. If only they did ...
I have this combination (SiS 760 chipset w/o dedicated RAM, mobile AMD64 CPU) in my notebook, and it's good enough to play the mainstream games. Sure, thanks to the inherent bandwidth limitation, you'll have to keep detail level low, but it works surprisingly well. The engine is a derivative of the previous generation discrete "Xabre" graphics chip.
In fact, SiS have always been pulling their previous-generation graphics engine into their chipsets ... from the 2D-only days of the 6220 (in 5598 chipset), then the first 3D chip 6326 later moved into 530 and 620 chipsets, the "300" DirectX7 chip moved into 630, 540 and 730. Currently we have the "315" in 740, 741 and 650 chipsets, and the "330" aka Xabre in 661 and 760. There's a plot behind all that ... SiS have been doing this for the longest time of them all, and within the constraints of doing that, they're doing it quite well. VIA and Intel have been much slower in updating the graphics engines; NVidia's and ATi's more expensive chipsets would be quite good as well, but they've always been missing the price point for integrated graphics.