I recently got most of them and the favorites are,

Tracks
Prowl
Red alert
Grapple
Inferno

I recommend getting the Encore ones to fill in the line when possible(Ironhide,Ratchet,Jazz,Trailbreaker and all the seekers).

 

True, for adults/people who buy for display purposes, the springs probably aren't a big issue. I do have a habit of placing myself in a kid's shoes when I buy Transformers (or remember my own mentality as a kid) and thinking I would've been sad that the guns on the HC reissues couldn't fire (other than Ultra Magnus). But yes, not hunting for tiny missiles is something I don't mind doing, especially with Tracks since his missiles are the smallest I think and the launcher part always falls off his head whenever I pick him up to move him.

 

As many others have said, the Commemorative Series were okay, but pale in comparison next to the Takara Japanese efforts (TFC, Encore etc).

My favourite CS was probably Bluestreak. I've been selling mine as the Encore versions are released (anyone want a CS Hoist!?!?!)

 

I only need CS Smokescreen everything else I will get from encore. Sold my CS Jazz, Starscream & Thundercracker and got the Encore versions.