The first bike I owned was a 1970 Honda CT90. Technically street legal but I never registered it for road duty. 'Twas a neat little offroad scooter and was one of the better examples out there. Wish I still had it because clean ones get bought up by collectors for a mint these days. I absolutely love classic Hondas.
After that, I had a 1981 XR250R and a 1986 XR200R. Offroad only. The XR250R was a beastly stump-puller. Everyone who rode it asked me if it was really a 350R with a 250R seat on it, heh . . .
My first street bike (which I own today) is a 1998 CB750. I remember sitting on one brand new in the showroom in 1998, and I fell in love - swore I'd own it some day. It's no wonder I ended up with one, I just had to have it
It didn't help that my brother had owned a gorgeous '80 CB750F, or that one of my buddies has had several CB750s including a sand-cast '69, or that the bike that I idolize is its close cousin, the CBX.