I like bike shorts for all but the shortest rides. I commute 6 miles each way and wear them every time and love them.
I have tried Pearl Izumis and Aero Tech Designs. My favorite is the Aero Tech Designs Top Shelf bike shorts. Expensive, but comfortable and durable. They come in sizes up to 5XL. I started with a 44 waist, am down to about 42, and I wear 2XL, if that info is helpful.
http://www.amazon.com/Mens-Shelf-Sho...+top+shelf+men
Good luck, I hope you find what works to make you want to ride every time.