This always starts those lame debates, but I'll make it quite clear which is the best.
Hp 568 for quite a few reasons:
1) The screen does not have gamma issues like the 38xx series of ipaq, and before the dust issue comes up, it only applies to early models, if you're buying a new hp 56x, the screen will be sealed.
2) Comes with cf builtin, rather than adding bulky sleeves.
3) Removable battery
4) Most (if not all) the problems listed at
www.ipaqpetition.com are not present in the hp 56x. (sd issues, etc)
5) All ARM apps will run on 56x just fine if the developer isn't an ipaq nazi. (eidos + ideaworks)
6) Builtin screen cover
7) sexiest device ever.
Oh, and about the joypad, there's the zeta joypad, dunno what the hanaho one looks like since well i don't own an ipaq.