I've been to exactly 100 gigs now, so I guess I'll make my first contribution to this thread:
1. My Dying Bride - They never, never, never play the States. Haven't since like '94. A friend from home flew to England just for the show. 'Nuff said.
2. Carcass - Never thought I'd get the chance to see them but then they reunited and I did. Best death metal band ever, one of the best shows I've ever seen.
3. Anaal Nathrakh - Similarly difficult to My Dying Bride to see in the States. Also saw in London.
4. Sparrows Swarm and Sing - They didn't exist for long, and I still hold that of the hundreds of live sets I've seen, theirs is my favorite ever.
5. Romance of Young Tigers - Saw them four times before they broke up, the last being my 18th birthday. Maybe my favorite post-rock band of all time.
6. Alcest - At the time I saw them they had only done a handful of shows total and only one or two others in America. Can't wait to see them again.
7. Isis - Saw them on their last tour before they broke up.
8. Immortal - Got into them a little too late to have seen them before they broke up, really really glad I got to see the reunion.
9. Wolves in the Throne Room - Suddenly easy to see with their extensive fall tour announced, but at the time (2007, right after Two Hunters dropped) this wasn't the case.
10. Iron Maiden - Not hard to see at all but each of the three times I've seen them has been a religious experience, reminding me why I love music. Toronto in 2008 especially stands out.
Mortals are mortar and life is the fuse.