If budget allows, Ahrefs is really the go-to tool imo - it has all the tools you might need on a daily basis as a good regional coverage (which is especially relevant to me) compared to other similar tools that might not have much data for less popular GEOs.
Btw, even the "lite" (cheap) Ahrefs plan is kind of ok and covers most daily needs.
In case you are interested in AI optimization, I can recommend checking out ClearScope. Probably less relevant for affiliate type of stuff, but I have been using clearscope when doing freelance
SEO (where people tell me "WE WANT AI
SEO!") and it's been saving a lot of time.