I'm gonna put "how big is your room ?" back in my signature, I think. If your room is big enough that M3s have trouble filling it you should go all out and get something bigger like 50s or 60s. If your room is fairly small then you're not missing much with M3s.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8