bleem DC looks better than PSX,but if your pc is powerful enough, it looks even better with ePSXe...allthough there's still a timing issue in epsxe, which can be fixed by turning the music off. The latest bleem! pc can run GT2 as well, but has glitches in the menu screens, otherwise it seems to be ok and can run at higher resolutions as well. However, the DC bleemcast is the most accurate emulation of GT2 for now, and yes, much better than playing it on a PSX.
I'll personally vote for bleemcast GT2 now, but the next ePSXe might surpass it. If you dont care for music and you have a powerful PC , then ePSXe is the best for you on this game.