BEST CONTACT MANAGEMENT SOFTWARE?

Greetings!
I wanted to see if anyone could suggest the best Contact Management Software or Solution? I’ve thought of several things, but I don’t really know what would work best. last year I tried Bebo, and that was a terrible idea. I’ve considered using Excel, ACT, Access, Yahoo Address book, and the address book in Outlook Express, but that’s about all I’m aware of. I thought maybe some of you may have ideas that I haven’t thought of. I’m looking at around 500-2500 addresses or so.

This is a really important issue to me, so I’m putting the points at 900, hopefully that’s appropriate.

Thanks so much
Rick