Keith Urban - Who Wouldn't Want to Be Me, especially while driving with the top down on my car on some back country road, prefferably winding.
Diamond Rio - How Your Love Makes Me Feel, just a fun song.
Shania Twain - Most of her stuff can put a smile on your face.
Dixie Chicks - Earl Had to Die, another really fun song, especially if you watch the video with it.
Peter Gabriel - Sledgehammer
Dream Theater - almost anything by them but especially the whole Images and Words album, just a great sophmore effort.
Most Tchaikovsky as well, though some can be a bit depressing at times.
When all else fails a good classical or jazz disc while curled up on the couch with my wife works wonders.
Steve