What will you use it for?
A little bit like how long is a piece of string That is very broad in interpretation.... However for general occasional use assuming no demanding situations then perhaps look at something like a Godox TT350, also a nice starter into the Godox flash ecosystem.General use, all and everything that warrants a flash.
Only one......ever? How is that even possible.The Godox TT350 is great as an entry to the whole Godox system.
But if you really only ever see yourself with one flashgun, then there’s loads to choose from Neewer, Godox, Yongnuo, Nissin (look for ETTL and HSS) but I’d be tempted to look for a s/h Canon 430ex.