Take your pick, they have a knife for everything and they know their shit so pick one and it'll be good to you if you treat it right. Not to mention Buck will treat you right if you're unsatisfied.
If your an American who's interested in Buck or just knives in general you MUST own the 110 and the 119, they dont get more American and iconic than these two.
If you want something small and lightweight potentially to put on your keys, then look no further than the 425 miniBuck or 283 nano bantam.
Then there's the 482 bucklite max there which is currently unavailable because they're redesigning it for 2018.
It's an awesome lightweight one handed EDC that's not too big or too small for a modern folder.
Need an EDC folder, Buck's got you covered from their 300 series slipjoints all the way up to the 110 or modern folders such as the marksman among many others.
Need a hunting fixed blade they've got you covered, from their hartshook neck knife sized bird and trout all the way up to the 120 general and everything in between.
Need a fillet knife Buck's got you covered folding and fixed.
Need a modern fixed blade , Buck's got you covered from the Mesa up to the hoodlum.
Need a bushcrafters type knife, again Buck's got you covered.
If you want a multitool check eBay because Buck made them, need a Swiss army type knife we'll check eBay again because they contracted with Victorinox to introduce the Swiss Buck.
They've got everything anyone could ever need in a knife if you don't also love carbon steel and patina.
I recommend any Buck knife that catches your interest