At the moment lancer/dragoon would probably be the best for you. A lot of the positional moves were eased/removed a patch or 2 ago. They do have a very long "optimal" skill rotation though.

Pugilist/monk has lots of combo possibilities for different situations. They are all pretty much 3 button combos but depending on the situation you want a different series of 3. They also have a lot of positional effects and need to keep up greased lightning stacks.

Rogue/ninja is easy for basic abilities and combo but relies on mudra/ninjitsu for a lot of the best effects. There are (at level 50) 3 mudra that can be combined in 9 different ways for different effects and the timing is somewhat sensitive.