You can do a lot of fun things in GTA V. This one's particularly good.
Here's what you do:
1. Play as Franklin.
You know you love playing as Franklin anyway.
2. Get a fast motorcycle.
Franklin's primary bike is too much of a hog, so if you can, get something zippier. Maybe an NRG 900 or a PCJ 600.
3. Turn on Soulwax FM.
I did not listen to this station enough the first time I played GTA V. (You can do this to whatever music you like best.)
4. Go to downtown Los Santos.
5. Start driving as fast as you can in first-person. See how long you can stay seated with the accelerator maxed out.
Drive as fast as you possibly can, either flooring it or letting up just enough to take corners and navigate intersections. If you're coming up on what looks like a dead end, it almost always isn't one -- you can usually take a hard turn or go off-road and keep moving forward. The crucial part of all of this being...
6. Rely on Franklin's special ability.
Franklin's special time-slowing ability is crucial for this. Use it every time you feel like you're losing control. Use it to corner, use it to bypass intersections, use it whenever you feel like you might crash. It's easily the best special ability in the game, and it will get you out almost every tight spot you get into.
7. Have fun.
Before long, you'll be threading the needle through rush hour traffic, soaring over parked cars, nailing stunt jumps, and generally moving faster and more recklessly than you thought you could. This activity is actually pretty fun without having to worry about the police, but it can also be enjoyable with a couple of cruisers on your tail. Don't get your wanted rating too high; keep it at one or two stars and things will stay just the right level of spicy.
Speed is the most important thing: Pretend that Dennis Hopper has put a bomb on your motorcycle. If you let up on the accelerator, it will blow up.
If you've been playing a lot of GTA V, you may have already tried this. Maybe it's old hat to you, or you've found some other interesting way to shake things up. (Please share if you have!) Regardless, speed-biking as Franklin is one of my favourite simple pleasures in the game. I've been having more fun with it than usual lately too -- I've found it much easier to handle bikes and motorcycles on PC due to the higher frame-rate, particularly in first-person.
So! Get on your motorcycle and put the hammer down. Good luck.