The SV650 is often the most obvious choice, but in all fairness, there are others.
LIGHTWEIGHT SPORT STANDARDS:
The 4-valve liquid-cooled DOHC inline-four Suzuki Bandit 400 is not imported to the U.S. anymore, but it was(is) one of a kind. Unfortunately, it is out-classed in every way by the SV.
There has never been a 525cc inline-triple Sport Standard.
The 4-valve liquid-cooled 90-degree DOHC V-twin Suzuki SV 650 made the Honda Hawk obsolete, but the SV lacks the Hawk's single-sided arm.
The 2-valve air-cooled 90-degree SOHC V-twin Ducati Monster 696 is another option.
The 2-valve air-cooled 45-degree pushrod V-twin Buell XB9 (984cc) Lightning is not my favorite, but it could work for some.
MIDDLEWEIGHT SPORT STANDARDS:
The Yamaha FZ6 and Honda 599 are 4-valve liquid-cooled DOHC inline-four Sport Standards, but they suck for some of the same reasons that 600 Supersports suck on the street- like a tepid torque peak at an elevated rpm.
The 4-valve liquid-cooled DOHC inline-triple Triumph 675 Street Triple looks like more fun than giving two toys to three kids.
The 4-valve liquid-cooled DOHC 90-degree V-twin Aprilia Shiver SL 750 looks like a real winner.
The 2-valve air-cooled SOHC 90-degree V-twin Ducati Monster S2R 1000 is another option.
The 2-valve air-cooled 45-degree pushrod V-twin Buell XB12 Lightning is not my favorite, but it could work for some.
HEAVYWEIGHT SPORT STANDARDS:
It's been a couple of years since the 4-valve liquid-cooled DOHC inline-four MV Agusta Brutale has been made in a 750 version, but it's still a good bet.
The 4-valve liquid-cooled DOHC inline-triple Triumph Speed Triple 1050 is the current rendition of the original bad boy. A little porky, but more powerful than ever. Truly unique.
The 4-valve liquid-cooled DOHC 60-degree V-twin Aprilia Tuono lacks for nothing.
The 4-valve liquid cooled DOHC 90-degree V-Twin Ducati Monster S4R (1000) is also at the top of it's class.
OPEN CLASS SPORT STANDARDS:
The 4-valve liquid-cooled DOHC inline-four Kawasaki Z1000, the 4-valve liquid-cooled DOHC inline-four Honda 919, and the 4-valve liquid-cooled DOHC inline-four Yamaha FZ-1 are three options, but I'm not a fan of any of them.
The 4-valve liquid-cooled DOHC 75-degree V-twin KTM 990 Super Duke and the 4-valve liquid-cooled DOHC inline-four MV Agusta Brutale (910 and 1078) look like winners.
OVER THE TOP SPORT STANDARDS:
The 4-valve liquid-cooled DOHC inline-four Suzuki Bandit 1250S looks promising.
The 4-valve liquid-cooled DOHC inline-four Suzuki B-King looks very competent. It doesn't look quite as bad in black. Maybe it would clean up a little with an aftermarket exhaust.
What advantage does a single-sided swingarm offer? Is it just less weight?
Ooops. Didn't read it all and had to edit my post to nothing. Nice post KirkP. When I pick up my Ducati this week I may have some questions for you!!
Quicker tire changes during endurance racing pit stops, without disturbing the chain adjustment and rear brake.
We can speed up rear tire changes (on bikes that do not have a single-sided arm) by doing things like attaching the rear axle nut to the washer, beveling the tip of the rear axle, polishing the threads on the rear axle, safety wiring the adjuster block to the rear axle head, making a safety wire "loop" (covered with rubber hose) to pull the rear axle with, and putting a healthy bevel on the rear brake pads, but it's never going to be as fast as a tire change with a single-sided arm.
We also use the sock trick- a rolled up sock wrapped in duct tape, wedged into the chain where it meets the rear sprocket- turn the rear wheel, and it drives both adjuster blocks forward before you tighten the nut. The chain adjustment should remain consistent- if you don't get the wheel all the way forward, the chain may end up too tight to allow smooth clutchless upshifts- or worse. Just remember to pull the sock before dropping the rear stand.
Shaving seconds during pit stops is easier than shaving seconds on the track.
Take a look at the Kawasaki Versys. It's been getting rave reviews both here and overseas. 650cc vertical twin 4 valve per cylinder, liquid cooled. Styled like the Triumph Tiger and Ducati Multistrada. Looks to be an excellent bike!
Those three bikes, along with the WeeStrom, are really kind of in a different category. I don't know whether to call them long-travel standards, or 17"-wheeled Adventure Touring bikes. They are nearly as versatile as a Sport Standard, though.