Gotta bear witness to my ur-lobster: The lobster roll at Lenny and Joe's Fish Tale in Madison, CT. It's just big chunks of warm, tender meat and butter overflowing a buttered and grilled split-top bun. $15.99 for a plate that includes decent fries and good coleslaw. I grew up in the area and my family's there so I get to see them when I fly cross-country to get my lobster roll fix. /snerk/ We usually go mid-afternoon in the summer because the lunch lines are ridiculous from the beach.
I had a lobster roll at a Bradley Ogden place called Yankee Pier in Larkspur, CA and it showed me I'm just not into any additions -- no shallots, no tarragon, etc. please. It was pretty small and cost quite a bit more, unsurprisingly. It was just off, having what I've enjoyed in a beachy, cafeteria-style place, in a sit-down, upscale restaurant proper.