Have about half a dozen in rotation right now but my two 'go to' razors are a Revisor 8/8 and a Palmera 14. Although I can get a nice shave with about any size razor the larger blades feel more comfortable in my hands and seem to go through my thick, course facial hairs with greater ease than the smaller blades (In other words, I don't have to be quite as focused about how much 'slice' I add to my stroke with them as with, say, a 5/8).
As others have already said, keep trying different sizes, grinds, styles if you get the chance. With experience you'll probably start to find size, grind, tip style (spanish point, ect.) will start to play less and less of a role.