Maybe it's a bit taboo with 'collectors' but I find it an interesting topic. How did you play with your toys?
From many people I hear they reenacted TV episodes and storylines with their figures, like acting out TF the Movie with their TFs. I never did things like this, a reason being I never had more than 5 or so toys from popular lines and mine were typically not the star characters.
What did I do? In order of which I remember doing the most (and I have a good memory of these things):
1. Building. I had a lot of Lego and Construx and would build many vehicles, fortresses, et cetera. It was always a good time consuming challenge to make do with the pieces I had. I particulalrly treasured Lego hinge-pieces for making robot mechs.
2. BIG WARS. Here I'd use the terrain of my house to set up massive battles involving all toys and scales, drafted from the toybox to different sides. These would involve everything from Joes to G.U.T.S. to Battle Beasts to MOTU to platsic army men to MUSCLE to Robotech (I had an Excalibur and I remember making that bad-ass mech a particular force on the battlefield). One battle I recall had it's only survivor be a plastic grey horse from a farm animal toy set.
Related to the "big wars" but much more formal were the dioramas I'd set up for my Mega Force, such as in a big tray with sand and stones for desert warfare or the neat detailed battlefield I made from a green-felt on hard board table covering type thing and trimmed fake plastic plants for trees, along with a a painted blue river.
3. Fighting Tournaments. Based upon either boxing-type or prowrestling type rules with KO counts and 123 pins, I'd clash figures in structured tournaments until there was a champion. I'd even lay out the figures in pairings to remeber how I had the battles set up. Either these would be a mixed-line class that would involve TMNT, MOTU, WWF, and other similar size figures (and the ruggedness of their construction and high-personality looks of their appearance suited them well for wrestling-type fighting) or, I'd have tournaments with smaller-scale toys that I had a lot of . Battle Beasts, and huge 64-man MUSCLE tourneys.
Sometimes when i see my box of MUSCLE I'll fight 'em a little. And everytime I buy a new Mega Force piece I have to line up the armies on my floor.