Responding from the other side of the "pond" as well. I spent the first 8 years of my career at a big center. Another year at a medium sized tower. 11 years at a "Combined Control Facility" that included area, approach, and "aerodrome" control all in the same place. My specialty was the area and a medium sized approach control - I did not work the big approach control and the tower.
However, having had time in each, I can say this:
1. There is nothing like the immediacy of clearing aircraft to take off and land. You say something and airplanes MOVE, right before your eyes.
2. You can scare the living p*** out of yourself a lot more in a tower than anywhere else.
3. Approach radar... Booooring. Cookie cutter control, vector to the downwind or the final, got the 737 in sight?, slow to 180, contact tower, same clearances day in and day out.
4. Area radar: different every day. You can craft a unique solution to every problem. You have to know a LOT more about a LOT of airspace than just a few miles around an airport. You get to work a lot of unique military operations what most of the world doesn't even know happen. I've worked the aircraft of presidents and kings, world record attempts and cutting-edge experimental aircraft, the latest military technology and the oldest of historic warbirds sometimes in the same day. Except at a very few of the largest and busiest airports, you won't see that kind of variety.
5. Area non-radar: It can be like watching grass grow, or it can bury you mentally as you try to respond to requests and figure out if everyone's still separated. If you like playing chess or even sudoku, you'll like non-radar. I had a love-hate relationship.
If I could only do one... I'd do Area. More varied, the most challenging, in my opinion. Contrary to what someone said up-topic, in the US, we'd send the ones who couldn't hack the center off to a tower somewhere, where they'd usually check out. If you can, try to vary things and move around a bit - if nothing else having all three licenses under your belt will be a bonus when you try for that fat contract job overseas!