It really depends on how you play.
If you like the primary section, try getting the marksman, impulse Minigun, even the ranger rifle if you can get it. The best two, though, are the photon shotgun and the bee swarm spell.
I don’t recommend getting a backup weapon, but if that’s how you play get the steam revolver or the Minigun pistol.
Say no to melee.
There are quite a few options for the special section. You can get the laser spear, pet dragon, barrier rifle, and the snow storm. The best one is probably the pet dragon, but it’s pretty spammy, so don’t be too annoying with it.
I don’t know if you can afford it, but if you can, get the prototype. If you can’t, though, for a sniper weapon try the tactical bow, the photon sniper rifle, poison hunter, or brutal headhunter. If you can’t get the prototype, though, don’t go for the sniper.
For heavy, I would get the alien cannon, bass cannon, apocalypse, anti-gravity blaster, or the hydra.
Hoped this helped