Honestly my "wish list" keeps getting more obscure. We live in a time when Xaaron of all characters got a toy.
Xaaron!
Anyway if the premise here is no limitations...
HasLab Brave Red Geist (Deathsaurus repaint)
Titan class Grandus
Commander class RiD '01 Megatron
Commander class Thunderclash
Commander class Dai Atlas
Commander class Powermaster Optimus Prime
Leader class
New Rodimus
Leader class Zeta Prime (honestly, the IDW or TFO designs are both good for me)
Leader class Cybertron Megatron
Leader class Big Convoy
Leader class Megazarek (Legacy Armada Megatron repaint)
Leader class G1 Skyquake
Voyager class Soundblaster (NF Soundwave repaint)
Voyager class Esmeral
Voyager class Lyzack
Voyager class
Kiloton (non gun alt mode that homages the MicroChange toy)
Deluxe class Browning (see Kiloton)
Combining Liokaiser team
Combining Road Caesar team