I like Talent Night, Icons, AndrAIa, and the early Season 4 ones (The later ones may be a little to into the series for newbies) I like Gigabyte, me'self and the one with Fax Modem and Data Nully (can't think of the name off the bat). Wizards, Warriors and a Word from our sponcers is always a classic. And to Mend and Defend could be a good one, but only after you show one with Bob in it. I'd still wait until you've got them hooked in.
MY favorite episodes are the last few of of Season three, but they may not be good to show to converts the first time round.
Random idea: Does anyone kinow how many hours in the series, total? You could have ReBoot Marathon sleep over thing! Round up all of your fellow booters in your area and each of them can bring a protential convert (or two, or three or ten) Then you can stay up and watch all the ReBoot episodes in succession and do ReBoot arts and crafts and all that jazz. That could be fun