Canada - 85/290 or 29.3%, 395 species
USA - a bunch...23 states, 559 species
Obviously, I don't have lists for many of these counties! This also brings me into another cool point which is that my Ontario 'total county ticks' just passed my ABA total ticks list (the total number of species in each province/state added together) yesterday with 2434 Ontario county ticks and 2384 ABA ticks. Of course, I currently only have lists for 38 Ontario counties, but have been to 48 (out of 50), so this probably happened a while ago. I'm also missing checklists for a few states from when I was younger!
Another exciting event (for me at least) was entering my 1000th checklist into eBird today, from Lemoin Point CA, Kingston. It had 36 species on it including the first Winter Wren that I've actually seen in several years (I almost always just hear them singing).