Randall knives and TOPs knives are pretty close to even as far as quality. Both are nice but both are made from 1095 high carbon steel (most models) and they're over priced if you ask me (1095 isn't that expensive). They're very good knives but you have to take care of high-carbon steel in the elements.
Ontario made the original RAT knives for Randall but the companies got into some legal squibbles and as a result, Ontario ended up making a D2-tool steel version of several of the Rat knives - which can be found for only a little more than Randal's 1095 versions.
D2 is good steel.
Don't get me wrong, I've owned 2 different Randal RATs and loved both but they are nowhere the Busse's I've owned.
Busse's (and swamp rat, and scrapyard knives - all companies in the Busse family), knives are almost exclusively owned by collectors so bladeforums is your best source for one.
Busse uses a patented super steel called infi (most scrapyard and swamp rat knives are not made of this steel) but its nearly stainless and virtually indestructible.
Swamp rat and scrapyard voth use a variety of steels (all proven) in their knives and are very solid.
Look at the Busse Active Duty for a good smaller knife comparible to the RAT3 in size. My personal favorite edc fixed blade is the Busse game warden.
Avoid the classic kabar - I bought one and actually used it in a camping situation (very light cutting / chopping) and nearly destroyed it.
Tried the same thing with the gerber lmf2 and it held up but lost its edge every 5 mins.
Tom Krein's knives are pretty awesome too but again - all owned by collectors.
