Get Juno 4.0, it works really well and it is the one I have. I have heard that Juno 5.0 stinks, but I have never used it.
Juno is far from the best ISP, but if you pay $9.95 for it, then it works better than AOL. Seriously! All you AOL users, get Juno 4.0 for $9.95! There is also the "Free" Juno, but it is really a trial in disguise. You get what you pay for...except when you are using AOL...