Always a shame on domestic redeyes...they kill you heading back east.

That being said, I was at least strategic with my LHR trip this week. Fly MSP-ATL-LHR on the way over (longer flight to sleep, plus it departs at 1050p, which is closer to my bedtime, thus making it easier to fall asleep), and return LHR-JFK, so shorter flight across the pond (which I'll probably sleep through a lot of since it's an 820a departure from LHR).