Recommendations from previous posters are great. Get a fixed, Izula, Mora, etc. if there is much dirt and possible prying.
If not, get a Recon 1 in CTS-XHP for long lasting edge, toughest lock in any folder, tough and ergonomic scales, a true beast of a knife. Or get the AUS8 steel version if you find a deal on one, they run cheap these days. It's a true classic of "hard use folder" recommendations.
The Ganzo G720 can hold up to real beatings, I can tell that from first hand experience. Mine has been through hell and come back many times. Dirty and rusted due to my lack of maintenance, but it keeps going. still cutting and locking perfectly.
Nice thing about Chinese knives is you can get lots of them for a low price and try lock types, shapes, sizes, etc. without worrying too much if you have to pry, scrape or do abusive tasks with them.
Some good Chinese folders to beat on for less than $15:
And my Spyderco Salts may not have liners, or be made with FRN scales, but they've held up after more abuse than most of my other folders. They're the wuintaessential light, tough maintenance free folders IMO.
Unless you pry with them, they'll cut, stab, rip, and do everything you may need a knife for!