Rocky IV

Yes, the final fight scene from Rocky IV between Rocky and Ivan Drago inspires me.  I think most hardcore Rocky fans would agree; Drago was Rocky's most formidable opponent in all of the six movies.

One interesting comment I remember reading on YouTube after watching the final fight scene from Rocky III between Rocky and Clubber Lang went something like this:

"This to me, was the best fight scene of all the Rocky movies, because it was the most realistic.  Are you trying to tell me that in between Rocky III and IV, Rocky somehow grew an iron jaw and was able to withstand 15 rounds of the same punches by Drago that killed Apollo Creed in less than two rounds?"

Excellent point, but it still for me never takes away from the inspiration I get from watching Rocky take down the big Russian (especially when I'm in the midst of a bad stretch).