I think both of them are fantastic...I'd say go with whichever one is less expensive.

 

Movie Prime for play. MP Prime for show.

Still... MP Megatron beats them both 

 

Leader, everytime I've stumbled upon cases-upon-cases of 20th Prime in TRU (at $100 each no less), or the DVD version ($140), I've never been able to think, "Wow, I'd love that in my collection".

In direct contrast, anytime I see Leader Prime, I feel the need to break down and buy it, putting myself further into debt.
(These movie toys got me broke already  )

 

The answer is simple: the more Optimus Primes, the better! Armada, Energon, Cybertron, Alternators, 20th, Classics....

Anything that isn't a monkey.

 

MP - easily the best TF I ever purchased.

 

qft  

 

I'd say MP. I love Leader Prime, but he's too disproportioned. He's just got too many giant pieces sticking off of him.

They should give the design to Bandai. I guarantee you if you got a Perfect Grade Movie Prime, it would look almost identical to the CGI version.

 

Masterpiece Convoy IS the greatest Transformer ever made.

Leader Prime is great...but it ain't no MP-1.