I use 1.7.2 that i recompiled for my machine, but Visual C++'s compiler has some issues with certain optimizations so some games don't work properly (Castlevania Circle of the Moon locks up at the intro screen where the text starts to get taken away from the scrolling story)... so I just went back to the default 1.7.2 and I love it! (PS/Disclaimer - I own all the Castlevania games for GBA, they're great!)