Here is pretty much my all time favourite Tau kit from Forgeworld - the Tau Tetras.
Why in the world would these be my favourites? Well, first they are very downplayed. They look almost unarmed at all, more like almost a civilian vehicle. This struck a chord with me when they were released. In wargaming, especially so in 40k, very often the "small stuff" is ignored. Scouting vehicles and such. One could argue that in the battles a regular game of 40k scouting units don't really have any role on the battlefield and I agree. Still, it's nice to see these almost cute little hovercars.
By the way, I recently also finished a Dystopian Wars fleet, you can see it here.
So if you're into steampunky, grand scale naval combat definitely have a look. The 2.0 rules have just been released a few weeks ago.