First "two-wheeler": a kid-sized racing bike (24" wheels) that my dad brought back from Greece, where he went with the navy
Later: a more average, American-made tool-around-the-neighborhood bike, brand unknown, but it was a gorgeous metallic forest green
When I started college: a Schwinn Varsity, robin's egg blue--too big in all but the standover height, but I learned at least basically how to use gears and toeclips by riding that bike; gave it away to a cousin eventually
First bike I got as an adult: a Trek something-or-other, also too big for me (shame on you, LBS guy, for selling me a bike that fit me so badly), but I rode it for a long time, and actually credit that bike with my renewed adult interest in cycling
Next: my Terry Symmetry, which fit me just right--delicious teal green color, triple chainrings, so much fun to ride I couldn't believe it. With this bike, I really learned to use gears and toeclips. Took my first solo long rides and my first multi-day tour on her. Lost to Hurricane Ivan in 2004.
For a brief time, I also tried out a used Bianchi Volpe that was great for riding around campus when I was in grad school. But alas, that bike didn't really fit me well either, so I finally sold it to a friend, who, sadly, doesn't ride it much. *sigh*
And now... after losing the Terry, I got a Waterford 1900 (called the "Adventure Cycle"--a touring bike). Waterford builds custom frames, but I got this one at a slight discount because it had already been essentially built for someone else and somehow the deal went wrong with that person. It fits me beautifully, and surprise--it's that same lovely metallic forest green of my second kid bike! I was able to get them to paint my nickname on the top tube in gold--Bad JuJu--so she's my strong and confident alter ego. LOL

I love my Waterford, but I must confess I've been hungrily eyeing the 2005 Bianchi Veloce at the LBS, and it doesn't help that people on this forum keep buying them and posting photos!