Most of the new owners of motorcycles like the Honda CBR150R, Kawasaki Ninja 250R, Tiger Boxer 250 RS or the latest Honda CBR250R will do some modifying to their motorcycle.
The first modification is often better tires, unless it comes with decent tires as standard – which is with exception of Tiger motorcycles unlikely. Most of the time manufacturers have to make a compromise in terms of grip or feel to handle the fact you might need exceptional two up stability, or for the rubber to withstand hours of riding bolt upright on a Thai roads in 35 degree Celsius.
Brands aside, the most important thing to consider when fitting new tires to you motorcycle is suitability to your choses application. You obviously wouldn't buy motocross tires for the road, in the same way you shouldn't buy track tires for the road, but many do. Consult the tire manufacturers, most have websites that allow you to set certain parameters and they recommend a tire and compound for that specific purpose. Also always fit the correct size or the new tires you've just bought for all that money will be wasted. Good alternative tires for the smaller sport and sport tourer motorcycles are available from Dunlop, Michelin, Pirelli, and Bridgestone – plus probably a few more.