Getting back in depends a lot on how you were when you got out, and how long you've been gone.

I actually went though this myself, I was out of the hobby for about 10 years. When I left, I was an instrutor pilot, and generally a pretty good all around pilot. I got back in when my father bought me a trainer as a surprise gift. I think I flew it 2 or 3 times before all the rust fell away, it all came back quickly. And I'm actually a better pilot now, since I'm older and wiser and less likely to do stupid things in a hurry.

So, if you were flying scale warbirds or doing wild acrobatics with a cap or extra back when you left the hobby, you could probibly jump back in with a Super Sportster-type, or better yet, a 60-90 size pattern ship. Pattern ships are very stable, and tend to stay where you put them. On the other hand, if you were just a bit past solo, and still worried about landings when you left, get a trainer, just get one with a flater wing and semi- or symetrical airfoil. Maybe a stick-type plane set up with mild control rates and a conservitive CG.

No matter what plane you get, you should get someone else to fly it first, shaking off rust and doing a test flight at the same time is a bad idea, IMHO. Get someone to get the plane up and trimmed, and have them hand it over to you, or use a buddy box. Yes, a buddy box on a pattern ship is silly looking, but you'll figure out pretty quickly if it all comes back to you or not, and you won't have a re-kit on your hands.

Good luck, and welcome back.