My friends and I started off playing D&D 3.5e in high school and college. We played it a lot over the years. Eventually we started playing 5e, and that’s mainly what we play today (on the rare occasions we actually sit down and play).
I had a friend who enjoyed experimenting with other systems like “GURPS” and “Swords & Wizardry”. We only ever played a few sessions with “Swords & Wizardry” but I enjoyed it a lot. It was an extremely lethal system where players were encouraged to be clever rather than solving problems through comat, since players weren’t particularly powerful compared to your typical monster or NPC.
Most recently, another friend introduced us to “Apocalypse World”, which we really enjoyed. We originally were just gonna play a one-shot, but wound up having a dozen or so sessions to keep the story going.
Noice. I multiclassed as a Monk/Sword Sage (from the Tome of Battle expansion) and had fun being my party’s enforcer for a long, multi-year campaign. Most of the rest of the party were squishy sorcerers and such, so I was pretty combat-heavy to balance that out. Some of the most fun I’ve ever had.
Our DM was kind of a jerk but he was generally a good DM. After that long ass 3.5 campaign I barely ever played with him again, but kept playing with the friends I enjoyed playing with more. Constantly did one-shots on the weekends when I didn’t have too much homework.