There's been some threads about livestock choice in this forum, but I'd look around for the ones about fish that have jobs in the tank. There's a lot of really cool fish out there, but it's also really really cool to not have to do maintenance on your tank because your livestock does it for you.
I can't speak directly to your tank compatibility, but things I greatly enjoy:
- A rabbitfish (foxface) - eat all the things, including bubble algae and commonly eat hair algae and and and. Easy to find, including small ones that probably can fit in your tank and easy to re-home because everyone wants one. I think general consensus would say a 65gal is too small, so your choice, but again you can find very small ones
- A bristletooth tang - another algae eater, though in my experience less impactful than the foxface. There's ones that I think a 65gal would pass the least aggressive tang police
- Lawnmower blenny - caveat I have not found mine too be useful at all for keeping things in control. Maybe it is, but far less useful than the others. Can be an interesting fish though since it's different
There's others too, like juvenile other tangs which I'm not going to suggest nor rag on someone for getting. Just be honest with yourself on if you'd actually go through the trouble of catching it and buying a new one if you're buying it because it's small. That's a lot of work, and probably most people won't do it.
Once you get your worker fish picked out, then figure out what other fish you can fit in. IMO that makes things long term more fun, even if you're not starting with the dream fish selection, because the best way to get out of the hobby is let it turn into a second job with all the maintenance.