REUs are basically the best thing you can do for your education as an undergraduate. Essentially there are no cons for any of them. They all generally pay for your travel, housing, and give you a nice stipend too. You get to experience a different part of the country, meet new people, and most importantly, work on research full time. They look great on graduate school applications. All of them offer these things so it doesn't really matter where you apply.
On the NSF website there is a list of all REU programs. They have separate lists for materials science and physics. There are many to choose from.
The main thing you have to worry about is that it is very difficult to get accepted to one because so many qualified people apply. In physics, the big name schools get up to 500 applications for about 10 spots. That should give you an idea of the competition involved here.
I've seen the list and picked out a few so far. Naturally I'd like to apply to the big-name REUs, but if there's a lesser-known REU that stands out for some particular reason, I'd love to hear about it.