Just go in chronological order, from around 150, the early one's are pretty tame, and the show builds up slowly that way. Dependent on your circle of friends it might not be a good idea to introduce them to the more ridiculous, anus-obsessed ones too early.
I don't think there is any place to start that is best. If you start at the beginning of 'new Podtoid', a lot of the current content isn't there. If you start at the most recent one and work backwards, you're diving into the deep end and I don't think Podtoid works out of the blue like that. Picking a an episode at random, somewhere between 185-210, is your best bet.
I do think that this is not a show that you can simply introduce people to and they'll immediately be on board with it. In fact, in its current form I think the vast, vast majority of people would be put off. Everything only really works as well as it does because it has all had a slow build up over 90 or so episodes. Hell, I've been listening to Dtoid's podcasts since the very first Podtoid, and yet I know even I would be like "what the hell is this shit?" if I wasn't familiar with the cast and show and was just randomly presented with one of the last fifty episodes.
So, go for it, just don't worry about picking one specific episode, because nothing stands on its own like that, and be prepared to switch it off after ten minutes because everybody in the car now hates you.
Sound advice. I'd say that the Tara and Max era is a decent place to start. I personally got in at Thirst World Problems and then immediately started working my way back, as it was the most recent at the time. Just make sure it isn't one with just Jim and Jonathan, as those are waaaaaay out there.