Lightbug: I like both games, but I prefer Embassy Chess.

Why? I like the structure of Embassy Chess.It is very regular Chess like in appearance. But even familiar looking openings are a completely new game. Though regular Chess often has amazing subtleties in slight differences in openings it often transposes into the same game or the difference matters little, and of course it has been studied for centuries. In Embassy Chess all this is true too, but even more so as it can very fast from the start. So far it seems to me that Embassy Chess is much more tactical in the beginning of the game which I'm sure is caused from having more pieces, and powerful ones at that, on the board while the King is still the same. The board is larger, but I think over all the power increase is more than the larger board dissipates as compared to the same pieces on the 10 × 10 of Grand Chess. Comparing those two games and a more or less harmless check in Grand Chess is often just a matter of moving the King back a square, whereas in Embassy Chess these checks can cause a major problem as the check often has to be blocked and you must be on guard for this.

Positional players will have a hard time against the tactical player, though I've played a few that play positionally. Unfortunately I am not a strong enough player to see if I'm right or not. I wish stronger players and regular Chess masters would take up Embassy Chess and give it some of the study they devote to regular Chess, but I suppose this can said of much variants.

Janus Chess is a good game. I don't play it as much as Embassy Chess. The power is almost the same as Embassy Chess, but the positioning of the pieces makes it play less like regular Chess. For those that like the random set ups, this might appeal to them. I think an interesting variant of Janus Chess would be to play it Extinction Chess style as it has the two Jauses and I'm sure this would add to the already wild tactical play of Extinction Chess.

Lightbug: In my preferences, it is:
1) Embassy
2) Grand Chess (because of the early promotion)
3) Janus