1. Iron Maiden - The specific reason I list them is because ever since I got into Maiden, I've seen them at least once on every US tour they've done (starting with GMETID). So, I'm proud of that.
2. King Crimson - Mostly inactive since 2004, save for a few select shows with Gavin Harrison as the 2nd drummer. I saw two.
3. Amorphis - Not such a big deal for Euro-people maybe, but they don't exactly come to the US regularly, y'know.
4. Helloween (with Gamma Ray) - Getting to see Gamma Ray and Helloween in the same night, and then the encore with Kai doing Helloween songs: awesome tour.
5. Queensryche - Not rare as a touring band or anything, but the Mindcrime (+ Mindcrime II) shows were damn awesome and I'm not sure if they'll be doing that again.
6. Opeth - Also not rare. But I've only seen them twice - On shows that were very rare. The chronology shows, and the recent 20th anniversary shows.
7. Heaven and Hell - They played a ton of shows, yeah. But the whole thing was pretty unique and felt special. Especially now that it's possible that the whole thing is over.
8. Mucc - Only played 2 headliners in the US ever.
9. Judas Priest - Just 'cause they're that awesome
10. Hiromi's Sonicbloom - Mostly just 'cause of awesome, but also because the show was actually in an NYU theater that was all amounts of kickass, instead of Blue Note.