IMO, the best upgrades were for the grenades, mines, and flares. They're excellent for crowd control. The SMG is worthless. The flame thrower is merely OK... it's good for slowing down a crowd, but it's easy to set yourself on fire and it really doesn't seem to pack much of a punch. The blade launcher, rocket launcher, and shocker are all good. The launcher and blade cannon are very limited in ammo, but can take down a large enemy fast. The shocker will seem weak at first, but when maxed out it can decimate large crowds very fast. Excellent weapon. The shotgun is your typical shotgun found in any game. Great up close, horrible at range. Didn't use it much.
I used the starting rifle in most situations and broke out the bigger guns for bosses. The mines, grenades, and flares were used to get large crowds off my back.
