SiS645DX for me.
I had 4 years of experience with SiS 5595 chipset on my Pentium II rig. Wasn't bad, pretty satisfied with it. My friend on SiS 735 chipset reported stability. Thumbs up for SiS.
I trust Intel for stability too. Currently I'm using the i850 chipset. The only thing I dislike about the i850 is that it's costly to increase RAM capacity :blackeye:. Otherwise an "A" for Intel.
I particularly dislike chipsets with integrated graphics (IG). It doesn't offer scalability so you'll get stuck with the IG for as long as you are stuck with your motherboard. My Pentium II rig comes with IG and I tell you I hated running PII 400mhz (slow) using software rendering (slower) without 3D accelaration (even slower) on CounterStrike (Worst!). CS is a relatively new game then. What's worse is that there's no way for me to upgrade the graphics unless I somehow disable the IG and install a PCI gfx card. :dead: .
Thus concludes my decision on choice of chipset...