I have owned several custom and commercial knives. I like Martin knives, but he no longer takes orders, he just makes some and puts them on his site to sell. I had good luck with a couple of Greg Wall knives, but he has turned into a ghost. Website up, but never answers emails, calls, texts, even snail mail. There has been a lot of discussion on knife forums that he is not delivering as promised, some going on 2 years past promised time. Depending on what you are going to use it for, I really like a Kabar. Been using the same one since 1973. Bark River are nice, but they do short runs of their models and then they are gone. Don't own one yet, but have heard good things about ESEE. Older Cold Steel are great knives, but once company was sold, they, IMO, have gone down hill both in quality and especially customer service. Ruana are great knives and I think superior to Randalls. The main issue being, is that they have not, nor appear to be, taking new orders for knives. I called 3 or so years ago and asked for the time frame of one of their bowie designs. Whoever I spoke to told me they will not be making any of their "classic" styles until they get caught up with orders that were already in. Like Bark River, they do make a few every once in awhile and post them for sale, but it is on a first come, first serve basis. There are a lot of great commercial knives out there, and some really good custom knives. If you are looking for a custom, you might try Arizona Custom Knives. They usually have a great selection of used customs.
