G-5e
So far, my favourite is regular Shogi. I like long games since I tend to naturally go for really long-term strategies--often a fatal flaw unfortunately, but I at least have better luck in a longer game. I enjoy having a variety of pieces as well. More pieces allow for more elaborate defenses and multiple mini-strategies. I like complexity and variety, so the larger a game is, the more likely I am to like it once I get the hang of it.
After that comes Goro Goro Shogi. Despite all the pieces having limited movement, it doesn't take long to get into the game because of the pawns being head-to-head right away. I also like that it's a bit longer than other small variants and it's harder to get a big advantage over someone than in something like Judkin's Shogi, in which a capture of a rook or bishop can easily turn the tables in a couple moves.