1. Bad or good files as to corrupt content.
Read http://reviews.cnet.com/5208-6141-0.html?forumID=8&threadID=28791&messageID=326953&tag=srch
2. Bad or good files as to behaviour.
There is no such database and even if there was, a programmer can call SVCHOST.EXE to converse with an internet site to siphon off your bank account information.
A recent exploit of Internet Explorer did such and by installing a keyboard logger would capture the keystrokes to/from the PC and as such was outside the usual defense of a firewall.
As such, you need to be ever vigilant with your antivirus updates, and run some Anti-Parasite Suite (Adaware, Spybot, Cwshredder, Housecall.) You'll also move out of the line of fire between malware writers and Microsoft by running either another OS or at the very least an alternative browser and even a non-MS email client.
Best of luck and do ask in the Security Forum.
Bob
I just got broadband service at my home and new firewall software to go with it. It tells me which programs are trying to gain access to the internet and a lot of them are unfamiliar. Is there a web site that lists common exe files so I know if they belong to "good" programs or if they are spyware or something else. I would like to delete them but don't want to mess up my computer. Thanks

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic