If you are just getting into EM's and your goal is to work on them as well as play, then a single player is the way to go. Much easier to get your feet wet with the relatively simple design on a wedgehead, than a 4 player beast like Wizard or Royal Flush.
My favorite wedgeheads are the early 60's, games like Slick Chick, Majorettes, Kings and Queens and Bowling Queen. Great art, and the gameplay is addictive!