Almost all software are Vista compatible now. Following are y recommendations:
Anti-virus: avast! or AVG in FREE and NOD32 or Kaspersky in PAID
Antispyware: No need. "Windows Defender" is good.
Firewall: No need. Vista in-built firewall is good enough.
Multimedia software: WMP11 rocks.
And all other common software, like firefox, WinRAR, 7-Zip, Winamp, IDM, FDM, FlashGet, Opera, Maxthon, Safari, etc are Vista compatible.
In codec Pack, I'll recommend "Combined Community Codec Pack". I faced a few problems in K-Lite Codec Pack in Vista, so I tried this new pack and its really cool.