@spines Cannot recommend
this enough. Not only does it work on every type of Turbo/PC Engine hardware (including my beloved PC Engine GT/Turboexpress), it will also run CD games (including on the Turboexpress, which wasn't possible before!) even if you only have the bare Turbografx/PC Engine unit itself. If you're only using a RF connection, though, you won't get audio -
this will allow you to get audio out for both CD and hucart and also give you composite out video as well (I've not used this - I've modified my PC Engine to output s-video and audio using the
Turbonanza, so if you're into modding and have an s-video TV, that's an option, too). In any case, the Turbo Everdrive Pro has run everything I've thrown at it without issue (though I've mostly played Castlevania Rondo of Blood on it, because, you know. Rondo.).
If you only want to play hucard games, the much cheaper
Turbo Everdrive v2 works fine. I had one of these before the Pro version came out, and it worked wonderfully, but yeah, no CD or Supergrafx games, just regular hucards.
The big box addon thing, the
Terraonion Super System3 Pro, is not something I've used, but it is a product made by assholes (the person who runs the company that makes them shit on krikzz, the maker of Everdrives, for escaping from Ukraine when the war started, for example), so I wouldn't recommend it, personally. I've heard it works fine, at least. It's less sleek than an Everdrive, anyway, and for me personally, the stock PC Engine console is so tiny and cute I don't want the added bulk on it haha.
EDIT: Oh and also, if you're looking at buying the Analogue Turbografx FPGA thing, note the Everdrives won't fit properly in the cartridge slot.