Not all south-facing windows are the same level of sun - if you've got blinds or curtains or nearby trees then you'll have more diffuse light - but for the purposes of this question I'll assume you're talking about bright, hot, full sun!
Cacti will definitely do well, but if you've got pets, small children, or just don't fancy picking spines out of your hand when you brush against a cactus when drawing the curtains (ask me how I know...), there are a lot of other sun-tolerant plants that will be great for you!
Echeveria (aka 'Mexican Rose') come in a wonderful variety of colours, and have a powdery coating of farina which protects them from sun-scorch. They'll put out long flower spikes in bright light.
Hoya (aka 'Wax Plant') are a vining succulent and in bright light they'll do interesting things like new leaves coming in bright red before fading to green, or having an increasing number of silver splashes. When mature they'll put out heavily-scented clusters of flowers. I can't paste the pics due to formatting but there's a good set of images
here
Other succulent names to look up: aloe vera (a classic easy-care succulent that can also be used in skincare and cooking), haworthia zebrina (pointy and stripy), haworthia obtusa (little translucent balls), pachyphytum oviferum (pastel and spherical), various forms of senecio (long strings and fluffy tails formed by small rounded leaves), crassula ovata (aka jade plant), sedum, and aeonium.
Oh, and while snake plants and ZZ plants are often recommended as low light plants, they're also absolutely fine in bright light too - they're super hardy and tolerate a very wide range of conditions.
In general I like to put succulents in my south-facing windows because I love succulents and keeping them anywhere else will often to lead to etiolation (stretched-out growth), and because they're most likely to avoid leaf scorch if there's a sudden heatwave. (I've had some lovely aroids scorched by the sun, so I'm speaking from experience!)
I actually freelance as a houseplant consultant - like a mix of a vet for plants and an interior designer / personal stylist for plants - and one of the things I really love doing is helping people find the right plants for them, taking into consideration their space, schedule, any pets/kids, access needs, etc. So if you (or anyone else reading) would be interested in some more personalised advice, do get in touch - I offer sliding scale rates
🙂
(Hope it's okay to mention that on here - I know employees of aquatic retailers aren't allowed to promote their stores, but there wasn't mention of freelancing - happy to have this part of my post removed if any admins feel it's crossed a line.)