Calvin and Hobbes off adventuring!
A lot of snowman jokes in this one. quite a few of Calvin and Hobbes wildly careening down slopes with Calvin holding forth on this topic or that.
Several of the cognitive dissonance ones where Calvin holds forth in abstruse academia or the the like -- the sort of strips that cause Watterson to observe that Calvin's not meant as a literal six-year-old.
There's a sequence where he and Hobbes plot against Susie, and one where he tries to get Stupendous Man to take his test for him. Several Spaceman Spiff adventures.