I hear generally positive things about Hegemon, but the aesthetic always seemed to blocky and rigid in my opinion.
Henkei Megatron is nice to have if you like the nerf gun alt mode, but in robot form, his back kibble/wings is just too ridiculous.
I've got Mega Steel Tronus/Granville as my go to CHUG Megatron right now. Sure, his alt-mode isn't perfect with the alignment of the gun barrel pointing slightly downwards, but in robot mode, he looks fantastic. Beefy, intimidating and armed to the teeth like what I expect a tyrant should look like. Coincidentlaly, Chimungmung
still has him on sale from their Black Friday special (supposedly) for just $40 + 25 to ship him. Even with conversion, that's about $85 CAD which really isn't bad at all for a voyager sized 3rd party figure.
For Galvatron, Mania King is a very good fit in the CHUG sizes. Looks very much the part in both alt and bot modes, and the lack of wrist swivels is not a deal breaker IMO. Speaking of which, if you're interest in acquiring Mania King is genuine, Ironwave, I've got a copy of the 1st release I could sell (shameless plug for myself, I know, lol). I even still have the original box with the foam insert he came in. Send me a PM if you want to know more.