Lake padden loop, and backtrails (Excellent for dogs, no leashes needed in backtrails)
Inter-urban trail (From Larrabee State Park to Boulevard park and downtown Bellingham)
The arboretum trail between Sehome High school and WWU, the little road right next to the dorm building, with the loading dock on your right.
All the trails up at Artist point, past Mt baker ski area.
Never done this one, but there's some other bird sanctuary or something off Lake Louise Rd. on your way to Sudden Valley.
Connelly Creek trail, very short, not terribly interesting, but not that many people.
Umm...
Oh the train tracks, starting from Post Point, down by the ferry terminal, and walking up them a ways is always fun.
I'm out of ones I can remember, but there you go.