8-bit Chip Showdown, PICs vs AVRs
It's been a time-honored tradition of hobbyists to argue over which series of 8-bit microcontrollers you should use, often boiled down to PICs vs AVRs. This makes it more difficult to get into the embedded hobby because there's a lot of pressure to pick the "right" one. This page is here to put this argument to rest.
It doesn't matter.
It really doesn't. Regardless of which side you choose, you're going to enjoy it. The decision doesn't hinge on the merits of chips because they're all so similarly featured. The knowledge you'll gain from either one will make learning the other trivial, so switching or even using both on the same project is a very easy thing to do.
There's one undeniable reason to choose one over the other: if a friend or employer prefers one side, just use that one. Being able to talk about it or share code/designs means more than every feature combined. If this isn't the case, I'd go so far as to recommend using both. They both have cheap variants and they're both easy to use and easy to get started on. You've got nothing to lose by trying both.
They're Not Going Away
Probably not, anyway. Whether or not you should use 8-bit microcontrollers at all, if they're still relevant, etc, is also a nonsensical discussion that comes up a lot. Most people that tell you not to use them say to just use 32-bit microcontrollers, because they're "better in every way, including power consumption." Whether they are or not (and that's another huge debate with no clear winners) is irrelevant. The most tangible reason not to go straight to 32-bit microcontrollers, in my opinion, is that they're not commonly found in through-hole packages, which means they'll often require fine-pitched pin soldering and/or breakout boards. If you're entirely new to the embedded game, that's too high of a wall to climb right off the bat. Even if you're an embedded veteran, that's not an insignificant amount of work and equipment to get a project rolling.
Say they are going away. 16-bit is the more likely successor, which are 99% the same as 8-bit chips, so you're not losing anything learning on the 8-bit lines anyway. Everything you learn will apply to larger chips, even 32-bit, so just cut your teeth on the easy stuff and have fun with it. You can always upgrade later.
There is an Exception
If you need on-chip USB support, in through-hole packages, PIC is the way to go. It's purportedly possible to do that with AVRs, but many PICs have an actual USB peripheral that's a joy to use.
Why Not 16-bit?
You can. If you go with PICs, they're indistinguishable. AVRs have them, but not in through-hole, as far as I can tell. With a lot of Googling, you can find QFP-to-DIP no-solder sockets, but they're rare and often expensive. Adapter boards you have to solder are cheap, plentiful, and pretty neat (and surprisingly not too difficult to solder), but I'd stick to through-hole until absolutely necessary to switch.
It really doesn't matter.
Just get out there and have fun.