TF fans!
Gun if you're looking at Alternators then I'd highly recommend that you check out Binaltech, if you'd like to go into the higher quality stuff. Binaltech is what the Alternators are based on, but there's a whole lot more metal and diecast in there. That's the good thing. Especially the early Binaltechs like Smokescreen are exceptionally well-made. They aren't too expensive IIRC.
The bad thing is that after some time Tomy-Takara decided to shell out whatever they have with the series and then make the same car with say a Decepticon instead of an Autobot character. And the quality of the later ones seem to drop.
Unfortunately Binaltech has ended now, along with the Binaltech Asterisk series which gives you an ugly figure of a random girl.
http://tfkenkon.com/collection/part6/act139/ BT Smokescreen
http://tfkenkon.com/collection/part6/act140/
This site also has loads of pictures for Transformers as well!
Masterpiece TF are all sure wins. Remember that MP-01 Convoy/Optimus Prime is basically the same as MP-04 (just MP-01 with a trailer

). Megatron is so realistic in his gun mode that customs confiscate it.
In addition I'd recommend the THS-02 Optimus Prime for you because it's both transformable AND posable. Check this out.
http://www.toyeast.com/v3/pdtdetail.asp ... =A02101825
My favorite has been Bumblebee in G1, because it's not too big and is easily transformable. It also looks pretty accurate to a Beetle too!