The best and cheapest performance mod I've made is to leave my wife at home.
Not only does it feel like the bike has an extra 10-20 hp, but it eliminates the terrible screeching noise at over 100 mph.

 

And lunch gets cheaper.

 

right???? agggggrreeed!!!!!!

 

You said "best" hahahahahahhahahaa


for real? go to fxxkbook, everyone has the best....hhahahahahaha gtfoh

 

124 inch motor, good tune, slight reduction in stock gearing. Not really tricks though.

 

1. Improve the rider's skillset.
2. Ditto
3. Same same.

 

I have no clue how much more concise I can get-
Your 3 best performance tricks would be the first clue.
Plus I cited a couple of examples.
Let's just let it go.
The wrong audience .

 

P*ssy. I go straight for the 100mg.

 

Obviously if you need the pill seems ***** ain't the problem...

 

Well, I for one thought this thread was a good idea, so I'll contribute.

1) Decent exhaust. Not "louder" exhaust for the sake of sound, but at the least, something with a crossover pipe and better flow characteristics. If I could only do a single mod for performance, this would be it.
2) A decent tune. Not a canned tune, or an "auto tune", or even a dealership tune, but some serious dyno time with someone who knows what the hell they're doing. Bike runs smoother, cooler, and stronger.
3) Cams. The right set of cams can make the bike perform the way you ride, giving you decent torque, decent horsepower, or both (to a degree). This one required #1 and #2, and usually makes a few other upgrades more important (if not entirely necessary), but the cams are the bingo.