Everyone around here seems to like the Acu-Rite brand combined thermo/hygrometer with a probe. They can be found at Walmart for about 12 dollars. Myself, I am still looking for one, since they don't stock them in my city (perhaps not in Canada at all).

(As an aside: is anyone willing to get an Acu-Rite and ship it to me? I can't find it anywhere here.)