An incomplete list of worthwhile songs to check out (ie ones I've found in the last six months or so, even if the albums are a little older). Thanks to Caroline, Kate, George, Mulldogg, and Lindsay for their rec's.

Radiohead - Where I End and You Begin, I Will, 2+2=5, There There, Myxomatosis (Hail to the Thief)
Nada Surf - Inside of Love, Hi-Speed Soul, Blonde on Blonde, Happy Kid (Let Go)
Flaming Lips - Fight Test, Yoshimi Battles the Pink Robots Part I, In the Morning of the Magicians, Ego Tripping at the Gates of Hell, Are You a Hypnotist?, It's Summertime, Do You Realize? (Yoshimi Battles the Pink Robots)
Red Hot Chili Peppers - Dosed, Can't Stop, The Zephyr Song, By the Way, Universally Speakin (By the Way)
Longwave - Everywhere You Turn, I Know It's Coming Someday, Tidal Wave, Ghosts Around You (Strangest Things)
The Soundtrack of Our Lives - Nevermore, Independent Luxury, Sister Surround (Behind the Music)
Aimee Mann - It's Not, Invisible Ink, Today is the Day (Lost in Space)
Andy Stochansky - Stutter, Here Nor There (Five Star Motel)
The Sleepy Jackson - Miniskirt, Good Dancers (Caffeine in the Morning Sun), Sunkids (Let Your Love Be Love)
Morcheeba - Blindfold, The Sea (Big Calm)
Archive - Again, Goodbye (You All Look the Same to Me), Cloud in the Sky (Take My Head)
Beck - Lost Cause, Golden Age, Guess I'm Doing Fine (Sea Change)
Liz Phair - Extraordinary, Why Can't I (Liz Phair)
Pete Yorn - Come Back Home (Day I Forgot)
Blur - Crazy Beat (Think Tank)
Eels - Fresh Feeling (Souljacker)
Oasis - Born on a Different Cloud (Heathen Chemistry)
Neil Finn - Human Kindness (One All)
Sparklehorse - Piano Fire, Shade and Honey (It's a Wonderful Life)
Linkin Park - Somewhere I Belong (Meteora)
The Roots - Seed (Part 2) (Phrenology
Junior Senior - Move Your Feet (D-D-Don't stop the beat)