oh boy...

1. some four-wheeled Preschool thing I rode down stairs and split my skull open at age 2 or 3
2. a fender skirted tricycle
3. first two wheeler was a too-big-for-me 26" tank bike from the 50s
4. first two wheeler that actually fit me was a self-bought 1976 Huffy Stars n' Stripes muscle bike (still have)
5. then I bought a Murray 10 speed with disc brakes to do my paper route
6. then I bought a used Schwinn 10 speed to do the route
7. new Huffy "Santa Fe" 10 speed to commute to work and lawn mowing jobs
8. new Peugeot 12 speed "Made in France"
9. 1965 Murray middleweight tank bike to restore
10. new 1986 Cannondale 12 speed road bike (Cyclone group, friction shifters)
11. new Trek 650 training bike (friction Cyclone group again)
12. Cannondale crit bike (race sponsor)
13. Cannondale 3.0 road bike "
14. Cannondale 3.0 crit bike "
15. used Univega mtn bike (too large)
16. 1989 Supergo Access mtn bike (still have)
17. 1990 Bridgestone RB-1 (still have)
18. 2003 Trek OCLV in USPS livery (still have)
19. 2009 Kestrel Evoke SRAM (still have)
20. 2009 Nashbar Touring Frame 105 triple
21. 2009 Nashbar Access mtn bike Shimano Deore (still have)
22. 2010 Windsor Touring bike (still have)
23. 2011 BMC SR-02 105 (still have)

and along the way:

1938 Roadmaster rat bike
1965 Western Flyer rat
1941 Schwinn DX rat (still have)
post war J.C. Higgins color flow rat
1944 Schwinn-made BFGoodrich Victory (now 700c SS) (still have)
1980-something Ross hybrid (still have)
1976 Huffy tt-style frame 10 speed USA Olympic clone bike (still have)
1980-something Bridgestone Kabuki (still have)
prewar Westfield mfg Seminole (current rat project, getting Nirve wheels)
1990-ish Ross bmx
1990-ish Vista mtn bike converted to a rat bike (still have)
1980-something Puch converted to a SS
2009 Ebay SS (fun cheap bike)


that's close to it... but I bet I'll be back to edit the list with forgotten ones.