Dogfish 90 minute is a winner in my book. I started buying it by the case.`
Also have enjoyed Racer5 (Bear Republic) as someone else mentioned.
Another similar tast which is excellent is West Coast IPA (green colored labels).
I agree Lagunitas (standard) IPA is somewhat weak, but I had a Lagunitas Corination Ale the other day on draft, and at 7%, it was actually very very good. Lagunitas Hop Stoopid (despite its name) is also an excellent brew!
I'm into the Belgian style beers myself, but during the warmer/hot summer weather, I tend to go with IPAs.