That is hard, of course, as many of you have done, it is hard to separate the car from where you were and what you were doing in your life at the time. But in order of ownership and not necessarily preferance some of my favorites:
1. 1966 AH Sprite, my first car, 1977, I was in High School, the car was not that nice, had been repainted an olive drab green, it had a few dents, ripped seats, but revving it up through the gears and the smell of musty british car and falling leaves on a warm fall night is forever etched into my memory.
2. 1967 AH Sprite, replaced the ratty car which quit for reasons I do not now remember. This one was nicer, had a built 1275 with a milled head and 3/4 race cam that went like a bat out of hades. I should have taken it for a longer test drive as oil pressure at idle hot was barely off the peg and it didn't get better when you revved it.
it eventually got a stock motor replacement and a bright red paint job and served as my car through college, did many crazy things in it. Let my girlfreind borrow it one morning when I was feeling a little "tired" from the night before, and she totalled it on the way home from work.
3. 1966 TR4A Solid Axle, BRG, O/D great car, great fun, drove it year round, learned all about rust and patching panels, but it was a reliable, stylish and practical piece of transportation, I was very fond of that car.
4. My first non-british car was a an RX-7. Mine was an 85, last year they made the first generation cars, engine would rev to forever and you didn't feel like you were straining anything, great looking, great handling, slick five speed transmission, perfect size, not too big, not too small room to throw groceries or a drunken friend under the hatch. Nice tourer with A/C and 5 speed, reliable, but still a sports car. Wish I had this car when my LBC club started running autocrosses.
5. 1954 AH 100, objectively as a car inferior to most any of the above, but as a rolling piece of art and being able to drive something which was raced and placed pretty much in stock form at places like Le Mans and Sebring, I felt special everytime I drove it.
6. 1968 Triumph TR250, my current ride, we are still early in the relationship, but she has potential to be an all time great.