My first solo was in a PA12. The instructor sat in back, so initially I could just pretend he was there and silently observing. But finally I turned around to look at the empty seat and for some reason couldn't stop laughing for a minute. Nervous hysterics, I guess.
My second first solo was in an Enstrom F28A. We were doing touchdown autos from 50' cruise, kind of like a quick stop. There was a bunch of FW traffic in the pattern of the uncontrolled field. Conscious of a FW on short final, I got the collective down, maxed the throttle, got the RPM to the top of the green, did a very aggressive departure to get out of the way and back into the mix. Apparently this fooled the instructor into actually thinking I could fly the thing. He says "I got it, it's too busy for this, we'll try something else." Lands on the grass, undoes his seatbelt, jumps out, and says "Go around the pattern 3 times, do a hover check before you go each time, then I'll get back in." Yanks the headset plug out and ambles over to the fence, apparently uninterested. This was when I learned that when you go from dual to solo, you had best run the trim to the right a bunch (Enstroms solo from the left). I picked it up and immediately translated left 15'. Not a great way to begin a first solo. But it turned out ok, though I think if I could have found my voice I would have told him "wait, I'm really not ready!"
The other memorable first solo in type was in a Schweizer 1-26. I had soloed the 2 place 2-33 already. It was a little more intimidating soloing my first single place glider. I got off tow with the traditional right hand climbing turn. The pawnee did its diving left hand turn. I just stayed in a right hand circle for a couple times around trying to gather my thoughts about what to do next. Finally it hit me that I should look for some lift. Looked down at the instruments and realized I had already climbed 500' and was going up at 5 kts. I'd rather be lucky than good if I could always arrange for it! Ended up being a great flight, a little over an hour, and ventured the furthest I'd been from home at that time.
-- IFMU