Any time PJ saves Max, but three that stand out in particular are:
In "Big City Blues", he jumps in front of a moving bus in order to save Max.
In "O R-V I N-V U", he leaps onto the back of a moving vehicle and exploits all the flaws in the RV using the chestnuts he had gathered earlier (see Heartwarming.Goof Troop) to save Max from kidnappers.
In "Max-Imum Protection", he manages to wake up from an apparently heavy slumber by hearing Max scream "PJ, help!" from almost the distance between their houses, and cut the rope the crooks were using to chase Max with safety scissors.
Pete going into an active volcano to rescue Peg's first anniversary gift in "Peg o' the Jungle", and then Peg going after him once it's shown he can't climb back out.