Solo Flight: unforgettable episode!
I was never a huge fan of Magnum, P.I., but I saw an episode every now and again because many family members/friends liked it. It's definitely an above-average show with likeable characters and a setting/premise that elicits many memories.
I definitely have not seen every episode, but by far my favorite and the one I can never stop thinking about is Solo Flight (Season 7, Episode 16). Some fans dismiss this episode as a "clip show" because of some re-used footage (memories/flashbacks). Yet even though it's very different from the typical Magnum episode (experimental, even), the series never was any better than this. They took a huge risk to do something very much off the beaten track of ideas but it works brilliantly.
The show's final shot still gives me goosebumps!