Sincere apologies from all of us who were being a bit paranoid mate. It's genuinely good to have you on the forum and hopefully you'll get used to us (and our odd ways).
Also a bonus to see you venturing towards an Audi away from Japanese cars (a joke of course. people on here will take the p1ss a bit but most of us value any well made car as long as it hasn't had a single bed glued to the back as a spoiler and neons underneath).
Other guys have covered the main points already but comparing the B5 and B6 side by side you will essentially get a bit more car for your money with the B6, and of course you'll pay for that. I'm sure everyone in the B6 section will tell you the B6 is a better looking car and in all likelihood a lot of the B5 owners would say the same. Most of us aspire to something newer unless we have an S car, RS car or something a bit special. The suspension etc is similar although not exactly the same on both cars. Like slepy said quite near the start of this thread the B6 has a 130bhp 1.9tdi engine option.
A B6 car will be newer, although of course it doesn't mean the specific car hasn't done more miles or been more abused.
I would question whethere there aren't many B5s around by the way. And I say this not to argue for the sake of it but I think they're fairly common.
I'll let the 1.9tdi owners tell you specifically how much power you can get out of one. If you browse the B5 section you should see what those guys are getting out of a 1.9tdi too. In both cases you can upgrade the turbo, remap them and do a few bits and bobs to squeeze out a bit more oomph.
Try to look at a B5 and a B6 side by side and then consider your budget. If you can afford the B6 I would suggest you'll be a lot happier with it. I certainly think that the B6 doesn't look as aged as the B5.
No need to apologise for a long post by the way
James - can you clean this thread up by deleting our irrelevant comments please mate?