Hm. Hard to say.
I suppose it would be my 'first' street bike. A 1993 Suzuki Bandit 400 that had spent 5 years sitting in a parking lot with a full tank of fuel in West Palm Beach FL. It had started as red, but the sun pretty much turned it pink. The shocks leaked, the carburetors were picky, and parts would randomly fall off (lost the shift lever once, made the trip home in 3rd, thank goodness I was able to time the stoplights right). Picked it up cheap and rode it through college after I got it running.
That said... I really miss that bike. It was quirky and really fun to ride. It didn't weigh anything and, while it didn't have a lot of power, it was plenty quick in the corners.
The one bike I've owned I'd not buy another of? GSXR750. Bought it brand new after finishing up PT from wrecking my SV650 (shoulder blade broke in 3 places). It was gorgeous in black and orange, and really fast. Very uncomfortable though. It was very much a bike built with a singular purpose in mind. I had a bunch of fun on that bike, did a few track days even, but it was not a bike you did miles on unless you really wanted to feel it later.