I want to cover what type of motorcycle coolant I use. Before taking my recommendation, please refer to your service manual as this post may not apply to your make & model.
My first choice is Pro Honda HP coolant, since it is readily available at my local dealer. It sells by the quart for about $8.
My second choice, and probably the one I use most, is Prestone Extended Life Antifreeze/Coolant . I choose to buy full strength jugs and mixing them myself with distilled water to 50/50. This type of coolant is available in 50/50 premixed for about $12/gal, while full strength is $14/gal. If I purchase a gallon of distilled water for $1 & full strength jug for $14, I can make 2 gallons of coolant for $15, or $7.50 per gallon.
The Prestone coolant mentioned above is phosphate, silicate, & borate free. Why is this important? Well, silicates can act as abrasives that may prematurely wear out water pump seals in motorcycles.