My favourite combiner will alwys be Predaking. The character was awesome and the toy was great, unlike the other combiners(besides Devestator) each of the Predacons were the same size, no 1 big robots with 4 arm/legs scheme.
Interesting enough, my first combiner that I owned as a kid wasn't a Transformer but rather a GoBot, the Renegade combiner Monsterous.
Come to think of it, he kinda looks like Predaking