Tri Shorts... hands down. I just did my first Tri and I wore the louis garneau Shark Power shorts. I was just going to wear swim trunks, but thankfully my bike guy talked me into the Tri shorts when I took my bike in for a pre-race once over. They were infinately more comfy than swim trunks on the bike or vice versa. Also, they were completely dry by mile one of the bike. They were very comfy in the water, and I had no chafing on the bike or during the run. Worth every penny!