North end of Pymatuning. There are several backwater bays that have close ramp access and are really good in the Spring.
North end of Wilhelm. The electric only portion above I-79 is well suited for yaks and small boats. Has lots of cover in the form of wood and weeds.
Tamarak Lake (near Cochranton). It's electric only and plenty of largemouth and muskies.
Justus Lake (near Franklin). Also called Two Mile Run Lake. It's electric only and has largemouth, smallmouth, panfish, trout, walleye, musky. Largies are mostly on the small side but the lake does conatin some giants. I've seen two 8 pound largies caught in the last 2 years. IMHO, Spring time and around the spawn is best.
French Creek. If you're ok doing a float, the creek offers riffles, runs, and some deeper pools, that hold smallies, muskies, northerns, walleye. Plenty of access. I'd suggest Utica to Franklin. That float would take you a few hours (at least) and offers good fishing.
Allegheny River from Franklin to Kennerdell. Plenty of access and you'll have to decide how long you want to float then plan your day. Lots of smallies and walleye, pike, musky.
A short disclaimer- If you're going to do French Creek or the Allegheny, your yak skills in moving water should be pretty good. Not that you'll hit "rapids" but some riffles will have you moving at a pretty good pace. Also, if you're using any PFBC access you will need to have your yak registered.