Hard one. Horizons and World of Motion at Epcot. The original Test Track and Figment and Listening to the Land when they had actual people in the boats instead of the now Living with Land.
Just about everything that closed at HS, especially those things that were around when it was MGM. Backlot tour (the original one), streets of America, stunt show, GMR (that one hurt a lot). I loved the old Hollywood theme it had before.
The original FWs at MK before they started projections, I'm height challenged and the projection shows are a waste for me as someone always gets in front of me. The gondolas in the sky at MK (yes I'm that old). The original bakery at MK, I'm not a Starbucks fan.