My 2 favorites are the Japanese Type 90 (what u guys are calling a T-90) and the Korean K1A1.
Type 90 (Japan)
Design wise it's quite comparable to the German Leopard 2A4. Uses the same Rheinmetall 120mm that arms most NATO tanks. Also armed with a 12.7 HMG and a 7.62mm coax mg. Max speed of 70km/h with a combat weight of 50tons. It uses an autoloader which means it has a crew of 3. The FCS allows either the commander or gunner control of the main armament, a first round hit capability whether it's moving or stationary.
Korean K1A1 (modified Type 88)
Hyundai is continuing to develop, upgrade and enhance the range of defense products it manufactures by using the experience acquired through the development and production of the 88 tank and other vehicles. The K1A1 is an upgraded version of the K1 MBT. Its lethality and combat firing range are much enhanced by 120mm smoothbore gun as its main armament, advanced day/night Hunter-Killer's capability improved Gun/Turret Drive System and new ballistic computer for 120mm ammunitions. The K1A1 basically retains the K1 MBT's outstanding maneuverability and technology oriented fire control system.
Korea's future tank: XK-2
The XK2 Main Battle Tank is a next generation of main battle tank to replace the older K1 and American M47/M48 tanks. It will be fitted with German MTU 1500 hp Europowerpack for the engine, and a new 120mm cannon with autoloader. New armor and sensor system are intended to be comparable to M1A2 and LeClerc
The Korean Future Main Battle Tank is under development as a indigenous tank to meet 21C digital battle field on the basis of development experiences of K1 and K1A1 tank. Important considerations in the tank are battle management system, automatic tracking system, automatic ammuition loading system, active defense system (soft-kill and hard-kill), navigation system, semi-active suspension unit, NBC overpressure system etc. The tank will be the main battle tank of the highest technical level all over the world.
