Both can be equally accurate
The most inherent accuracy will be found in bullseye target guns, such as a Smith 41.
Telescope
Factory, I'd probably say the 500 Magnum
Mine are very accurate to about 50 meters.
Blue Book of Gun Values
"Best" is too subjective to define for a hand gun. The biggest, the most practical, the most accurate, the most concealable, and the most durable pistols are all totally different guns. Two very popular models are the 9mm Glock and .45 caliber 1911. Both are used extensively by law enforcement and military personnel.
Super soaker 8000
The question can't be answered as written.
Value is too difficult to be accurate without seeing the gun. Condition which includes the amount of original finish and original configuration will determine value. Recommend taking it to a gun shop for appraisal.
Right hand "a gun". And left hand "the World"
There are several very accurate air guns and rifles. Air rifles used in the Olympics are the finest. As an example the P75 Biathlon competition air rifle will cost you around $2,623. BB Guns on the other hand are not very accurate beyond 30 feet.