Hate to give a complicated answer to a simple question, but it really depends on the game. On JM, rip the spinner and speed around the orbit as fast and as many times as you can. On a game like MB or any game where the ramps are unique or interesting, it's the most fun to hit those. Least fun is any sort of target, with the exception of single playfield drop targets like in CC or 24. Those are a lot of fun.