I've dreamt in what-my-mind-translates-the-ANSII-to, so that would have been after a bit of a DF overdose[1]. I've dreamt in Minecraft blocks. In GTA-world (to be honest, could be any one of a number of similar things, save for the obvious causation on top of the basic correlation). As driving Carmageddon cars, as being in Digger/Pacman universes, basically everything but Pong.
I most like dreaming in obviously-CGI-worlds that aren't specifically game-related, but then hate myself for never getting around to implementing that particular interesting landscape/concept in a game of my own, once I awake, as I'm obviously underutilising the inspiration granted to me. (But some concepts are being kept in mind for when I
do get around to developing such things... The bits that aren't obviously derived from some other influence... though I've seen concepts appear in other games
since that I'm now not so keen to be apparently copying, although it proves they were considered good ideas by others as well...)
The other night (nearly posted on the non-game forums about this, but restrained myself at the time) I dreamed about verbally proofreading some particularly badly spelled/grammared book, towards someone of note, and I believe this came from having read a certain (different) game forum the previous day in which
even the official moderator messages were all... wrong... just wrong. Like "where" instead of "we're"; always the wrong "their"/"there"/"they're"; basically all the stuff I hate and which gives me minor headaches, and would never (intentionally, Pedent's Curse permitting) allow to creep into my own posts.
This was closely followed by dreaming about watching a strange episode of Have I Got News For You (long running topical news quiz, on TV here in the UK, this one must have been based around the mid '90s as the host was the permanent host of that time, rather than the rotating guest host applied to the format since this guy left after becoming the news), and then listening to The News Quiz (long running topical radio news quiz) with even more strange elongation to this. This despite not having seen HIGNFY for ages, and only listened to the currently active TNQ several days earlier. I then woke (about 3AM), and when I returned to slumber I was back to the more unmemorable standard dream-fare that is of even lesser note to anyone who cares to read this thread, even if I could muster enough details to describe it in the first place.
[1] No such thing, I know, but I don't think "rightdose" is a word.