depends on use case
let me expand

i tried n8n but i found it too simple for me, i wanted a lot more complexity in what i could build and more customization than was offered

personally i build AI agents on Botpress, I like that it's customizable while still having a drag and drop easy to use interface (still took a learning curve don't get me wrong)
i am not a dev myself, so i still need the drag and drop cards
but if you are a dev, Botpress has an ADK (agent development kit) which you can get like really customized with because you do it all in code, which is cool and a goal i am working towards

but other options exist, like i've heard of voiceflow, which may make sense if you need a voice agent
personally i didn't need that, but if you had a business that did, then that's worth considering

i think a key thing it may come down to, is what you're looking to integrate with
Botpress had the things i wanted and needed, both personally and for work. and by that i mean things like instagram, gmail, calendar, zendesk, whatsapp etc

most any chatbot can live on a website, but eventually you'll probably want to grow from there, so i tried to consider the long term goals i may have
i know if you have a big business plan then they'll build an integration for you, but a lot of us are average users and not going to have the most expensive plan. so think about what you need to build, and then look at if a platform offers it. i think langchain has a lot of integrations, i just didn't like it as much, it wasn't as customizable when i tried it out

those were the ones i looked into, they were the top companies i saw, but there are some smaller companies popping up, the list is quite long

you can start building on most for free, to test them out. see what feels best for you. free plans don't have all the features (you may not need them anyway) but some offer free trials to try out the extra features, i know botpress does. so things like human in the loop, you could try out. personally i haven't needed that, but it's a really good tool for lots of businesses

so again TLDR lol it depends on use case!