I recommend Norton SystemWorks as well. I've got the 2000 version in my Win98 SE PIII Dell, and the 2002 version in my Win98 SE/Win 2k Pro/Win XP Pro AMD (Athlon XP 1800+), and it works well in all environments. The 2002 version has a feature called "One-button checkup" that includes a Registry Scan, Program Integrity Scan, Free Space Check, Virus Definitions Check, and an Auto-Protect Check (more virus stuff). It's pretty user friendly and should take care of most issues.
BTW, agree with you about Win XP. It's like Win 2K, but with a hula skirt on. Hate the frilly, "web feel" of the interface (although you can disable that and make it look like classic Windows), and generally don't like the idea of first run OS's anyway. Might as well not bother with it until a 2nd Edition is released (if that even happens). Although, I must say, it was a breeze to install. It was the only one of the Windows versions to recognize all the random pieces of hardware I put into this machine. I literally had to do no work.