Which one do you recommend?
Without doubt the PICkit-2
but that's probably not any help at all, but I haven't programmed Atmel chips for around a decade, so cannot really say what's good or bad in that department.
For advice on which AVR programmer is best/cheapest, perhaps you should make a new subject, to make sure those that know them will reply.
If anything, I could tell you to get a ready build and well proven (and easily updated) device. With the PIC's, it's often more expensive to buy a second source programmer which is usually inferior to the manufacturers own product - I don't know if Atmel makes USB programmers, but if they do, they should know how to make them good