Personally, I use Shell Rotella-T 15w40. I've been running it in all of our bikes, with no ill effects.
It's 11.99 per gallon at most Autoparts stores around here, you can even get it at Walmart.
I'm sure there will be many people on here that will tell you only to run the $10 per quart stuff from the dealer, and that's fine if you really feel the need to spend that much on oil. But, I'm guessing you aren't going to be doing any serious racing, so I doubt you really need the highest performance oil.
Rotella-T is a good quality oil. I ran it for many years in my truck. And in that application, we only did oil changes every 15,000 miles. If it can handle that, it'll be just fine in your bike every 3 to 4 rides.