For a fixed blade you are on the right track with the ESEE. They are well made, have good ergonomics, and are a great value. For a step up in materials take a look at Bradford knives. I’m fond of the Bradford 4.5 & 5.5 as well as the ESEE line in a similar size. Lastly, I’d recommend taking a look at Bark River Knives. They are another step up in price from the Bradfords but are very popular in the Bushcraft community and are made in my home state of Michigan.
For a folder I always recommend the Spyderco Paramilitary 2. It’s simply a great knife and is available in many different steels. I always thought Spyderco made ugly weird knives and resisted trying them. Don’t let the ugliness fool you, the Para 2 has great blade geometry and ergonomics. I’ve always been a Benchmade fan but their knives simply don’t cut as well as my Spydercos So I’m a convert.