That's shocking that HoM are your #1, JayKeeley. I never would have imagined!
MY LIST:
1) Kayo Dot/maudlin of the Well. After being gay for a few years and expecting this band to be a bunch of Opeth clones, I finally saved my heterosexuality by falling lin love with all 4 excellent albums this band(s) has produced. Songs like "The Manifold Curiosity", "Birth Pains of Astral Projection" and "Gleam in Ranks" are examples of songs that are so goddamned good that I couldn't have imagined them actually existing.
2) Genesis, obviously. I was first introduced to them when I was about 8 and was always touched by and interested in their old material, which sort of scared that little chubby 3rd grader. When I bought "Selling England By the Pound" on CD earlier this year (I was previously relegated to cassettes, some dubbed from LPs), my love and nostalgia were re-awakened ten-fold.
3) Godspeed You! Black Emperor -- GYBE are one of those bands that tricks you. You buy a CD and say "Wow, that's really good, but I only need one of theirs... There's no need to buy any more when I have one representative album!" I fell into this trap with Yanqui UXO when it came out, but decided to buy a few more of their albums late this year. Fucking AMAZING stuff!