I am agreeing with all these people saying Seismitoad. Just awful. It doesn't have the strength to take out anything, and personally I'd rather Poison Point to Poison Touch. I trained Tympole in the hopes of it becoming incredible, but no... Maybe if I had of EV trained?
Emboar is bad too. It's so sloooooow, and pretty frail. Frailty I expected in a Fire-type starter, but I was hoping for a little more speed.
Beartic has one of my favourite designs, but by level up it doesn't get enough Physical moves for type coverage, and TM options are slim.
Those three, along with Leavanny (who I adore, I think it's a 1000x better than Parasect) made up my team as I went through the game, and I really struggled with them: I also trained Munna and Tympole/Eelektrik, and they were bad too. I regret not reviving Tirtouga earlier, Carracosta is incredible (and thank god I didn't pick Archen, its ability is awful).