I've had many bikes over the years, but without a doubt my favourite is my SV650S. It handles unbelievably well, and the V-twin makes the bike so forgiving of gear choice through corners, and best of all, it's not fussy to ride like other bikes I've owned, which require the perfect engine speed and gear choice, plus precision riding 100% of the time. Unlike other bikes I've ridden, my SV can be corrected mid-corner without upsetting the apple cart. It's a total pleasure to ride, whether you're hammering it, or just cruising along. It also drives comfortably in city traffic, and never chugs along like a high performance engine that requires it be kept above 4500 RPM or more.
The best thing about the SVs is that they are virtually a blank canvas, on which you can upgrade and individualise to your heart's content. I've changed so many parts, I've lost track. It's like an obsessive hobby, which I gain so much enjoyment from in the process.
With a few modifications these bikes can keep up with anything through the twistie stuff. In fact, it's the other bikes that struggle to keep up, as I can ride the wheels off my SV because it's so simple and light to ride, whereas the overly temperamental R1s, GSXRs, etc, are struggling to man handle their bikes through the corners. It's alright if you're an accomplished racer, but those bikes are a pain in the backside for us mere mortals, and believe me, I'm a good rider, and never drop to the back of a pack, and most often sit in first or second when I ride with other experienced riders.
My point is, if you want to have lots of fun on a bike that allows you to explore your true potential, this is the bike for you.