I recently looked into ESEE alternatives and I decided on a swamp rat. I would say that Swamp Rat markets their knives as being somewhat superior (and more pricey) than ESEE, and Busse takes the next position in that hierarchy. The more pricey part is definitely true, but the superior quality is a more complicated (and disputable) question. In the end, the decision for me was really all about the SR-101 steel, which I chose over ESEE's 1095 and Busse's INFI.
TOPS is another brand that makes more expensive ESEE-type knives.
Out of all of these, I think that it is pretty much beyond dispute that ESEE gives you the most for the least money.
There are other knives that I would choose for other purposes, but that is partly because they are a different type of product. For example, for a dedicated hunting knife, I would choose many other knives before ESEE (bark river and dozier to name two). And if I knew that I would be working in a wet environment, I would choose a good stanless Fallkniven or Bark River over a 1095 ESEE. But now we are startin to get into apples to oranges.