Honestly I'm not a HUGE fan of any of them yet, but overall Seasons gives the most bang for the buck and is the most inclusive of all the packs. Its one expansion that I feel they got right in TS4 with the weather being different in all of the worlds, having all sims react to weather appropriately, and the calendar feature which allows for more customization of events on top of the pre-made holidays. I feel like I end up playing with Seasons more often when I do play because the weather dictates how my sims go about their day. If its raining out, they might spend the day inside watching movies, playing games, working on skills, etc... If its a clear fall day they hang out at the park or do some exercising outside. Its also great for those of us who have gardening sims because it makes the gardening aspect more realistic since you can't have all your crops growing year-round save a few.