I have 4
Red Hot Chili Pepper - it was about 7-8 years ago in the Phoenix Park, my first proper concert (I'm not counting feeder), got to stand on my mates shoulders for By The Way seeing all the crowd was immense.
Arctic Monkeys - about 3 years ago maybe 4. Saw them in malahide Castle, I did a load of sneachta and it made the gig a million times better they played every song they had at the time brilliant.
Eminem - last year at Oxegen. I had a ticket to see him before but he cancelled and went to rehab. Finally got to see him and it was worth the wait, played around 30 songs and was the perfect end for a perfect weekend.
Limp Bizkit - In September i think it was. Been a fan for as long as i can remember, got in the pit for most of the songs, easily one of the best gigs i've been to.
Also there are only 3 bands I want to see and I get to see 2 of them in July
Blink 182, Foo Fighters, System Of A Down,.