Apple IIgs Emulation

I've tried Apple IIgs emulation on Windows Vista about 2 years ago but with disappointing results. It never really ran as perfect as I wished it would. I used to do this on my old Mac and it would run perfectly, but on Windows the programs seamed to be unstable, they crashed, had problems recognizing disks and what not. I'm going to try again. What software do you guys recommenced. It has to run and play nicely with Vista.