For 2008, KTM won the 85cc shootout, however there are more things to consider than someones opinion on what bike is best. Pick a bike that suits your riding style and size. Also, it doesn't matter how good a bike is, if you don't have a shop to help you with getting parts and technical knowledge, your bike is just another bike.
the ktm 105 is way faster that a ttr
The KTM 105 is a good bike if you are transferring from a medium sized 4 stroke to your first 2 stroke. It has plenty of power. If you ride hard you might be better of going for a 125 you will be able to ride it longer.
90mph
105 mph with out modification
MSRP $4,598
Kx 100s are easy and cheep to fix. Ktms are great motorcycles but they can be more expensive to repair. Kx 100
80 +/- without mods
br10ecmix
Stock it will be in the 100-105 mph range.
stock 105-110 mph
80 +/- depending if you don't have modifications
70 ml