This is going to be highly specific, but for many years I have yearned for a remake of the "Stunt Mode" from San Francisco Rush 2049 on Dreamcast. I've played knockoff stunt driving games, but nothing is as good. I've played it emulated, but my experience with Dreamcast emulators so far has been fairly rough. Emulating the N64 version works better, but that version is a step down from the Dreamcast. So, I wait.
A sequel or remake of Battle Engine Aquila would be awesome.
I'd love a good version of Monopoly. The last big computer/console release was crap. Lots of room for improvement in speed, options, and AI.
And a true hardware replacement for the Atari 2600 paddles. It's been a couple of years since I looked seriously, but everything I've seen has problems with speed, jitter, homing, or something else. Admittedly, part of the problem is that the original tech had lots of flaws.