I used F-Prot for a long time.
It is a very reliable and very good antivirus! Really great, though sometimes its says there's a virus somewhere where there isn`t!
It can be a pain since its very through in its searches.
I remember one time it was saying that it found a virus in a PAK file of a game! (Quake3)
Very detalied and precise!
Anyway...just my opinion!