What terrain?
Personally for just general laning i always used a comp4 front and a Mitas C0-2.
A Bridgestone Gritty(i think the 663 not the 661....can someone confirm which is the better one??...been a while since i last used one) is another decent front tyre.
The AC10 rear tyre isn't a bad tyre but my choice would be a C0-2 over them due to their longevity with a decent grip on all terrain.
I did once try the Mitas front tyre which i hated but the lads i rode out with thought it was OK. Strange but true that.
Saying the above,my 2t 250exc came with AC10's so i am currently using them(with caution) but the front seems OK on a 2t compared to on a 4t but this could be due to less weight on the front end during engine braking. I'd rather bin the AC10's if riding a 4t though.Another strange thing.