RMK wrote the book on fixed blade design IMO - they are tremendously efficient knives, and their 01 steel is first rate for ease of sharpening, edge retention, and ductility.
Busse makes the most rugged fixed blades you can buy, and it's tough to find fault with most of Jerry's designs. The factory Busse edge is a little thicker than the Randall, but that can be changed. INFI is more resistant to corrosion than 01, but I think it's harder to sharpen.
I don't care for Strider fixed blade designs, and prefer CRK in S30V. I prefer RMK and Busse to any other "production" FB, and I'd put Strider, CRK, Fehrman, Ranger, SRKW and probably Mad Dog in a solid second tier.
If I could only have two large fixed blades, it would be the RMK Model 14 in 01 and a Steel Heart. Choosing only one or the other would be impossible.