I love both CL & GT but I can't imagine playing without GT. I use the club system a lot and Windenburg is my favorite world. The clubs are by far my favorite thing in the game. I use the build/buy items in nearly every build in some way or another.
GPs are tougher for me to choose from. I'm loving the new Vampire pack and I use SD and OR a ton but overall I'd say DO has been the best for my game play. I love taking my sims out and seeing other sims in resturaunts having dinner with their families or friends or spouses. The customization in the resturaunts is great too for creating unique little places for my sims to go out.
SPs it's a tie between Backyard and Kids. Nearly every kid in my game collects void critter cards and uses the puppet theater in the park so Kids probably has a little more use for me. I love the wind chimes, water slide and bird feeder in Backyard though. The big round table is also a must for every house in the neighborhood that has a patio.
