Unless you want to shell out or end up getting a cracked version of one of the best two AV's out there (Kaspersky/Nod32), then I wouldn't bother using anything but Microsoft Security Essentials to be honest.
Some of the others are kinda okay, but those have the most friendly interfaces, best detection rates, low false positives (what you're complaining about), the lowest system footprint, and least resources used during scans. They have advanced heuristics too so they can detect things that aren't even in databases yet solely by the way their code is written, and I think that also helps contribute to really low false positive rates.
The only false positive I ever saw with Kaspersky was... well, a crack for Kaspersky. More specifically the dll it replaced in the Kaspersky directory, but I think that makes sense since it would assume some malicious program has tried to alter its code. You can set directories or specific files to be ignored though, so even that wasn't a big deal.
The most popular two Norton & Macafee have absolutely terrible false positive rates, use high resources, and don't have very good detection compared to Kaspersky & Nod32 - so stay away from those two.