Ok, here is a start. The usual caveat, some of these will be suitable for some hosts but not for others. Fees and payment methods often vary between markets, so check them thoroughly before signing on the dotted.
When registering with the big guys, it’ll also give you a presence throughout the group, e.g. if you’re on BDC, then you’re also on Agoda, Kayak, etc.
Other than the big operators at the top, they are in no particular order and a bit EU oriented, simply because that’s where I am. There is a bit of duplication from the “in home” topic, but that’s just the way it is.
I’ve purposely omitted all the aggregators, like Hometogo and the sites that also manage the listing, like Onefinestay, VaCasa etc. I’ve also left off some of the more niche operators, and those with fairly small inventories.
Feel free to suggest additions to the list that may be of use to other members outside the EU.
Needs no explanation, IB only and a pretty rigid no cancellation by hosts policy. Appears to work better in some markets than others, as regards cancellation rate and guest quality.
The old Homeaway from Europe now rebranded. IB not mandatory but ranking will suffer and allows for hosts to cancel, financial penalty free (I’m sure, but not 100%). Registering with them gets you a presence throughout the Expedia group, places like Hotels.com etc.
Parent company of Vrbo, depending on your location, when you try to register with Expedia (as an STR) it’ll redirect you to Vrbo or Stayz or whatever site their algorithm thinks is best!
https://rentals.tripadvisor.com/
We didn’t get much from them, but I know folks who’ve had a fair bit of business through TA. Owners dashboard a bit clunky, but easy enough to navigate. I’m sure that registering here also gets you listed with Flipkey and Housetrip, as we are listed on Niumba, the Spanish version.
Chinese market mainly. A bit of a faff getting set up, but if you get guests from that region may be worth a look.
Discussed on here before, use search for hosts feedback.
Women hosts only, and again, use search to see previous discussions.
Might be handy for those with tents and 'vans.
Good for the German market, once Germany ceases to be a country sized petri dish of Covid we may activate our account there again.
Russian market, one I came across recently. I think it may be a collaboration with TA, but not sure.
https://www.spain-holiday.com/
Good for Spanish hosts, I know a few folk who use this’un almost exclusively.
Another Spanish one, part of the Idealista property group.
Worth checking out, no IB and low fees, I believe.
Limited market penetration geographically just now, but expanding.
https://www.thefreebirdclub.com/
Over 50’s only 
UK only, may be worth a look.
Again, UK only.
Looks like they’re picky about the properties, doubt we’d get a look in 
https://www.tuivillas.com/gb_en/
Appear to be UK and EU oriented, minimal coverage elsewhere.
https://www.interhome.co.uk/?ab=nt
Again, UK and EU mainly.
Appears to be for larger properties, just makes me think party!
I think that’s enough to be getting on with.
There’s a cold Estrella 
with my name on it in my plaza right now as it’s fiesta time, albeit somewhat muted in comparison to before.
JF