For $80, I'm not sure you're going to find anything that'll be much of an upgrade from the Frontman. To get a really great sound out of an amp that size, I think you've got to go up to the $150-$200 range. That's where you'll find your used Fender Champs (silverfaces can be found every day on ebay for around $175), which kick a whole ton of ass. Another great amp in that range is the Epiphone Galaxie 10. I don't see a lot of people talking about it, but all tube and pretty fantastic.
That wasn't an encouraging response, so I hope folks will chime in with some different opinions.
do a search on ebay and see if you can find yourself a Peavey Classic 20. I have one and it kicks. 15 watt, all tube, 10 inch speaker. Looks like a little Fender tweed amp. Kicks some sonic butt.