The best 250cc street bike
A good Classic Ninja specimen is a phenomenal bike. I've had mine five years now, and I bought it new. It replaced a flaky GS500E I was tired of trying to sort out.
Ninjas are the best 250cc all-street motorcycles, period. If you're looking for an economical bike, or a beginner bike, well, you can deny it if you like, but someday you will want to ride fast highways, perhaps to meet friends or family two states away, and these bikes can do it. By contrast, all the Japanese 250cc cruisers are at their limit on 70 mph highways, assuming they can actually get up to that speed. The Honda CB250 Nighthawk is basically the Honda Rebel cruiser in standard drag, and while it is a more comfortable size and seating position, it not only has that same low top speed but has a drum front brake for more exciting stops (plus it was discontinued). The Yamaha Virago--sorry, V-Star 250--has more oomph, but is more expensive and yet comes with a standard (non O-ring) chain, and is still a bit on the slow side. The Taiwanese KYMCO Venox can do highways a little better than the non-Kawasaki Japanese 250 streetbikes, and is very comfy, but build quality is suspect. Also, you can't cruise all day in top gear because it's too high-geared, so you need to go down a gear for much of the ride down the highway, which you can do all day in fact, but it makes you wonder. The Korean 250s can ride those speeds, but their engines have a reputation for self-destructing when ridden hard, which you sometimes have to do because, well, they're air/oil-cooled 250s.
There has been some life shown by some of the dual-sport 250-and-unders, but that's another story. If you want a pure streetbike, the Ninja's the one to beat, and it hasn't been yet.
Why? Because when you're on an interstate on-ramp, the Ninja's motor is just waking up as you merge, where the other Japanese 250's are tapped out. That can be very unsettling.
I bought my Ninja in 2005 because I wanted something brand-new, and it fit my budget. I bought a Suzuki DL650 V-Strom in 2007 because I'd always wanted one and my budget had grown, but I've still done a couple 400 mile days on the Ninja since then, on fast interstates, and it was right at home there. Sure, it feels like a toy at first when I ride it right after riding the V-Strom, but I quickly get used to its lightness and then I just grin from ear to ear.
I haven't ridden the next generation Ninja yet. If I owned one, I would probably farm out the valve adjusts to a dealer with a shim kit, and might also want to do something with the seat, but they seem like pretty righteous motorcycles as well. I admit they are very, very pretty, and have seen them performing admirably in the wild, flying down interstates in traffic. But I'm probably keeping my 2005 for a very long time. I know that I would miss it if I ever gave it up. I will still take my V-Strom when I want to go for very long rides, for the sake of my own frame, but I plan on doing some long days on the Ninja this summer (2010), for the grin factor if nothing else.