2006 Suzuki GZ250. Bought at 3100 miles and I've already gotten it up to 3750. I've been wanting a motorcycle for ages, and I knew better to not start on something too powerful. It's so fun to ride! And comfortable, too, unless I'm on it for 3+ hours, which I do without even knowing because of how fun it is.
Although there is an itch to get something more powerful now. I won't be able to afford the insurance on that though lol. To get that feeling, I test rode a Harley Davidson Sportster 48, not what people think of a "fast" motorcycle but it might as well be a rocket ship compared to what I have. But I'm super happy with my GZ250 and will keep it through at least April 2024.
I've had bikes since the early 80s. I've had from 50s to 1100.
I consider a 250 the bare minimum. It's not the bike per se, but rather that you must be in command in traffic. I would say at the beginning the sweet spot is 350-400 .
Later on I believe 500-600 is fine for most people, and even in this range you can find rockets like Rs and RRs.
Now I ride a sport maxiscooter, a Yamaha Tmax, which handles like a dream, has plenty of kick, is happy at 150-160 km/h, and comfortable as hell. This particular bike is the reference in it's segment (which it pioneered) for a reason. My mechanic calls it a proper bike in disguise.
I guess age takes it's toll.
It's definitely good enough for around town and even on the highways near me. You gotta go pretty far for the speed limit to get above 55mph where I live (although people don't follow that), and I can keep up in the slow lane at 60-65mph.