I watched Jackie Brown only once, but I can understand what arsaib means. I also wonder if i wouldn't like it the most if i saw it again... 
As of now, I've seen Pulp Fiction the most, and it's my favorite. Reservoir Dogs is one of the best "stage-play" films I've seen. Maybe too thick on the morals, but i also like it. I've only seen Kill Bill Vol. 1 so far, and it would be the weakest of the bunch for me, though i still like it very much.
I wonder what tarantino will do next. I hope for something more toned down like Jackie Brown.