The IPA that got me started was actually Stone Ruination. It was just so damn hoppy that I could barely drink it at first. But it was all I had left in the fridge and I was determined to have a good time that night (was going to a rave). Forcing myself to drink it did just as advertised on the bottle. Ruined my palate for lesser beers for awhile. It's kind of like diving in the deep end to learn how to swim, but if you're up for that, give it a shot.
If you want to go more gradually try hoppy red beers first maybe. Stuff like Ritual Extra Red.
Lagunitas IPA is a pretty weak IPA that seems popular. Not my favorite but I consider it IPA light.
Ballast Point Sculpin (or Big Eye) was a great suggestion.
Here are some comments on Stone Ruination from beeradvocate.com:
"The taste jumps up and runs a goddamn number on your palate. Hops, hops, hops, and more hops. The hops have a huge pine taste surrounding them, kind of like drinking a liquid tree. "
"An alpha acid hop-drop kick to the tongue is pretty much how I would describe the Ruination IPA. "
"The flavor is wall-to-wall hops, but it isn't as abrasive as expected. A tidal wave of hop flavor hits the taste buds instantly and maintains its intensity through the long, bright, hoppy finish."
If you really want to get into hops.. that's the way to go.