I like that last one. Is it the connection in particular that you think looks off? I don't see anything wrong with it, but I guess it depends on what sort of terrain you are planning it to have. Personally, I'd either widen the land bridge a lot, maybe remove the western gulf entirely, or remove it and create a narrow passage between the seas – but not for any geological reason, just because I think I'd prefer the look, so if you want a really thin land bridge you should definitely keep it as it is

I do think moving the northeastern island a little bit south would improve the map, though. That or expanding the map northwards. The island almost tangents the edge as it is, which from an artistic perspective isn't optimal.

Finally, just a thought: have you considered viewing the map as black=land? That's actually how I thought it was first. Then, if you want that land bridge, you can expand (what is now) the eastern peninsula on the western continent so it connects to the other shore. Something about that layout appeals more to me than when white=land, but it's just a matter of taste (or something) so do what feels right