TFC's stuff is all around the 13inch mark just like feralrex.
Warbo's and ToyWorlds is closer to 14.5 with the exception of TW's Devastator that is 20.

MMC is working on a Defensor right now that I believe will be around 16 inches. And if they ever reveal their rumored Abominus he'll likely be similarly sized.

And yeah like other people have mentioned Transformissions Menasor is gonna be big also, bout same size as warbos stuff I suspect.

 

Whoa hadn't heard this! Can you provide a link? Or were you referring ot the Maketoys version?

 

If you're into large combiners, try finding one of the ko oversized superion and throttlebots (only the first three are available yet)

 

They only teased some renders of their hotspot so far

http://www.tfw2005.com/boards/trans...ocular-max-maximas-pro-hot-spot-defensor.html