Offhand;
Lots of stuff by Aberfeldy (Love is an Arrow, Slow Me Down, Vegetarian Resteraunt)
Geneva (If you have to go)
Belle & Sebastian (My Wandering Days are over),
Coldplay (as mentioned before; non album tracks as well, like For You, Ladder to the Sun, Moses)
Cosmic Rough Riders (For a Smile, Now that you know)
definately lots of Damien Rice (Cannonball, Cold Water, Volcano)
Embrace (Gravity - also maybe the original Coldplay version of that , I wouldn't wanna happen to you, Drawn From Memory)
Idlewild (Blame it on obvious ways, Love Steals Us From Loneliness)
Keane (somewhere only we know)
The Reindeer Section (You are My Joy, Grand Parade, I'll be here when you wake, Cartwheels, Cold Water - not the same as the Damien Rice song)
The Seahorses (You can talk to me, and Love is the Law for the sheer cheek of some of the lines....)
Snow Patrol (Batten down the hatch, Chocolate, Make Love to me Forever - maybe a bit upfront?

, Velocity Girl)
Travis (Only Molly Knows, Flowers in the Window, Love will come through, Walking in the Sun)
Um... that's all I can think of without breaking out the CD collection.