[Crazy Jetty]

I would say ignore everyone's comment "Collect this, don't collect that."
Collect what you like. Every line has great figures, and complete rubbish figures. Every TF line. No exceptions.

So if you like the Animated Shockwave, go ahead and get it. If you prefer Classics Starscream, go ahead and buy him. And if Cybertron Optimus Prime seems like the coolest one, go ahead and roll with it.

If Transformers is just a side project, then I think you're far better off buying toys that seem cool to you, over trying to exclusively adhear to one line. Especially with the rest of the rather insane fandom going... well... insane over stupid things and driving up the prices to rediculous levels.
I think you'd be much more satisfied with a collection that you enjoy than one that conforms to the standards of a fandom you're not really apart of.

That said, screw 'em all. Nothing outrocks Beast Wars! Also, it's a really cheap line to collect because "ZOMG! NOT GEEWUN!!!" There are very few really pricey pieces, and they're usually onscreen characters.