Omega RYNO-4-Ever
When fully upgraded to level ten, it was renamed as the Omega RYNO-4-Ever, sporting a maximum ammo capacity of 900, with each laser having 5141 damage, possibly rendering it as the most powerful weapon in the entire RYNO series, due to the fact that if all 900 rounds of ammo were used up, the resulting amount was 4,626,900 damage.
The RYNO IV was often criticized by many players for being vastly overpowered, as it could destroy the last boss of the game, Emperor Tachyon, in a few seconds.
Source: http://ratchet.wikia.com/wiki/RYNO_IV