I don't have links as of now, but here are a few:

Heol Telwen (death metal with celtic themes, celtic whistle/flute throughout)

Tuatha de Danann (from Brasil I believe, but a really good celtic metal band)

Also should mention Falkenbach, Finntroll and Korpiklaani, more or less "folk metal" but have a strong familiarity to celtic music and can hear some influence, at least to me anyway... if you like the celtic metal bands, these should have enough in common that you would like them as well.

Also as mentioned:

Elvenking, also would say more "folk" than "celtic", is a great band, and agreed their old stuff is better (try Heathenreel).

Cruachan of course, though they NEVER tour.

Eluveitie just played in my area a month or so ago, was busy and couldn't make it....