Strictly speaking, Chet's and Red Robin aren't fast food chains, they're in what I believe they call the "casual dining" sector (they have table service and whatnot). Beyond that, this is kind of too broad a question to answer accurately. I mean, there are a million-zillion fast food chains now, and I can only think of a couple of dozen off the top of my head; and that's only the ones on Earth. Who knows what they're hitting the drive-thru at on Reticula Prime right now?

That said, you can pretty much assume that any fast-food place you can think of has at least one example kicking around somewhere in the 25th-century galaxy, although not all of them will be survivors of the pre-Contact era; some are revivals, like those modern companies that use old-timey IPs for branding purposes.

Examples that are readily found in New Avalon: Wienerschnitzel (most of which also have a Tastee-Freez in them), Jack in the Box, all the various KFC (depending on where you are in the galaxy, the C might not stand for Chicken)/Taco Bell/Pizza Hut permutations, and Dairy Queen. Dairy Queens are required by Avalon County law to be the kind that have burgers and stuff and not just seasonal ice cream stands. For reasons which are obscure to outsiders and even many Avalonians, virtually every one of the city's many Tastee-Freez locations that isn't in a Wienerschnitzel is in a Chinese restaurant, by virtue of which said restaurants also sell Big T burgers and fries along with their more traditional offerings.

The city also has one lone Hardee's out by NAU for studio in-joke purposes. Also, in the "fast casual" borderland, you have things like Johnny Rockets, Five Guys, and that Tex-Mex place I can't think of the name of that's slightly fancier than Taco Bell.

And of course there are Shyam Shacks everywhere, not just in Salutown, easily identified by their jaunty yellow roofs and giant revolving shyam-hoop signs. If you need a paper cone full of noodles and meat that you eat with a miniature oil filter wrench, and you lack either the time or the sobriety to sit down and unfold a napkin, Shyam Shack is your best pal.

--G.
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Benjamin D. Hutchins, Co-Founder, Editor-in-Chief, & Forum Mod
Eyrie Productions, Unlimited http://www.eyrie-productions.com/
zgryphon at that email service Google has
Ceterum censeo Carthaginem esse delendam.