Very difficult question to answer and a very dangerous question to ask, it can open up the "us and them" can. I'd probably say that if you are undecided or don't really have a preference then just go with whatever you get and you'll probably really enjoy it. Personally I went in thinking I'd love to sit in a tower staring out watching the birds get airborne and fly away, I had great fun doing the Aerodrome course, still remember all the great times I had on my 6 weeks training I did at Gatwick, am always up for a visit into a tower where ever it may be, and will sit at an airport waiting to go away and watch the movements for a while. However you'll have to fight hard to get my radar ticket changed over to tower. The thrill of moving aircraft all over the sky and making them miss while they climb out or descend in, or being the first to help when they REALLY need it, can give you such a buzz when you walk away knowing what you have just managed to do. Every seat in every ATC position be it Area, Approach or Tower has the ability to provide that so I wouldn't worry too much about what you would prefer to do, just go and enjoy what you actually get.