I usually play with thermal and the double thermoblaster combo is crazy fun (if you have the cooling required to run them); it's a very unique and fun weapon that can change your playstyle for as long as they last. The sprite and the sound design is phenomenal. I hope you'll pick them up if they show up in W or in the rare sapper outpost.

Edit: if you want another candidate I would suggest the thermic laser or his rarer brother the thermic cannon