I've been smoking various meats the past two years or so. I've tended to try to get good at one thing (spare ribs, wings) before moving on to others. I've tried my hand at spare ribs, baby backs, wings, country style pork ribs, brisket, pork shoulder, chicken breast, and a turkey.
The ribs, wings, turkey, and chicken breast have all turned out great. The ribs took a few attempts to really get down (I recommend cooking a bit hotter than suggested). Wings are a huge hit. I am surprisingly a big fan of smoked chicken breasts, adds a ton of flavor into a typical boring meat.
I've only tried a brisket once, it was out alright, but not blow you away good. Same with the pork shoulder.