Crystal hot sauce. This is a sauce that seems to be widely used in US recipes, and while it's not widely available in British supermarkets, it is available from specialist food shops. It's forever associated in my mind with Tex-Mex and with Brent Allen's notorious Champion Chilli. Crystal is a mild sauce and flavoursome enough to sample straight from the bottle. It's not too spicy but does lend a distinct flavour. I prefer to use it in cooking, rather than as a condiment. It would compliment any US or Mexican recipe well.
Frank's hot sauce. There are a lot of variants on this. I was initially unenthusiastic about it, finding it not spicy enough, but there are lots of good uses for this. If you use it as a condiment, you can be very liberal with it. It's a very vinegary sauce, so it gives a real tang to whatever you pair it with, and an easy heat. I find this goes very well with a pasta and cheese dish, provided the sauce itself isn't too tomatoey. Think Marcella Hazan's ragu. The tang cuts through the richness of the pasta sauce.
Tabasco. This is the original, probably the first hot sauce that most people in the UK tried. It's famous as a condiment and still works well for that purpose. It's actually rather hot for what it is, it's really quite expensive as well, but a little goes a long way. For years I doused pasta in this stuff, completely overwhelming the flavour, but now I prefer Frank's for that. Where it really shines is as a sandwich condiment, just a small amount really adds zing to a cheese and lettuce sandwich. It's also widely used on pizza but I think Frank's might work better here.
Encona West Indian Hot Pepper Sauce. This stuff is not a US import unlike the previous ones. It's powerful stuff with a fruity flavour and an intense kick. I went through a phase of using this for a condiment, and I still do occasionally, but you have to be ready for this stuff: it completely overwhelms the flavour if you put it e.g. in a sandwich, it's too strong to use in cooking, it can goes well as a foil for plain rice, combined with yoghurt. The flavour of this is an incredible achievement, though; I salute the makers, even if I don't use it all the time.
Flying Goose Sriracha with Extra Garlic. This is my go-to sriracha. It's highly addictive and works great as a combo with peanut butter, or it also works great on improv toast.
Yellowbird Habanero. I last tried this in 2019, I've never seen it on the shelves, and can't comment as to its flavour.
Clementes Jacques Habanero Chili Molidos. This might be my favourite thing ever, it was devastatingly hot, though I haven't been able to buy it online or ages. I used to have to order 6 bottles at a time.