After watching the teen girls squad episodes numerous times, I would have to say that Deathkillers parody is one of the funniest things i haver ever seen.

And the best StrongBad e-mails would have to be:
1.Kids Book
2.Sibbie
3.Stunt double
4.English paper
And the funniest would have to be Credit card, as long as you have seen a few e-mails beforehand and know who Homestar is.

Favourite character would have to be Homsar, i just love "I was raised by a cup of coffee"