I love the summer. Why? One word: Bikinis.
Other than that, camping, boating, cold beer, fishing, hiking, cruising with your windows open and stereo cranked, cool summer nights, no heavy clothing, shorts, sandals, tans, barely dressed babes, making your girlfriend scream with the bedroom windows wide open, chilling outside in the evening with friends, barbecues, cold homebrew, restaurants with patios, sex in the lake, naps on the grass, driving through the mountains, more cold beer, man, you name it!
And, last years highlight? Skinny dipping in Jackson Lake. My buddy Trev and I threw our trunks in the inflatable raft (my dog LOVES the raft). My girlfriend had an evil moment and took the raft ashore. They threw in two blue sand buckets. The beach was fairly crowded. We weren't wusses. We donned the buckets, ran up to the shore and got our suits. At least they had to look at our butts when we headed back into the water.