Jak

The original Painkiller absolutely should've been on this list! While it may not necessarily have heaps of weapons, each weapon has two firing modes, and several of them allow you to combine them to make a third mode. The base weapon you start with (aptly called the Painkiller) has a primary function of a spinning blade as a melee weapon. The secondary function launches a device that can slingshot enemies through the air in full ragdoll beauty. If that device misses any enemies and hits a wall, it will attach to that wall, and if you keep the device directly in your crosshair, it generates a laser beam between you and the device. Furthermore, if you hold the primary button while pressing the secondary button, the spinning blade launches through the air, going through any enemy it touches until it hits a wall. That's essentially four ways for your base weapon to cause damage. Now that's impressive!