I couldn't. There's isn't just one that would meet a person's every need. - Jack Carlson

probably facebook, just due to the sheer numbers of people they'll know on it - Duncan Riley

FaceBook... - Mona Nomura

Ditto Duncan - Charlie Anzman

Duncan hit the nail on the head. Your question implies the person has never done it before, so I'd probably say Facebook, not because it's my favorite but because it's perhaps most likely to familiarize them with the concept, find people they know/like, make them comfortable, enable fun, etc. - Anthony Citrano

Yeah, I'll have to go with Facebook too. So many people that are on there that aren't on other social networks that it makes it something I'm more sure about. - AshTR

I think it depends what their goal is. As a student, I use FB totally different than someone that's an entrepreneur would use it - Phillip Jeffrey

FriendFeed cause even people i knew in "RL" on facebook don't talk to me and friendfeed is more conducive to getting friends i've found - Cecil Sandus

Facebook. That's the easiest to understand. Twitter or FF are more for the advanced. - Winston Teo

FriendFeed is my preference, but as already pointed out it is for the advanced user and Facebook has way more users, so there's a much better chance to connect with folks they would know on Facebook. I suspect that will change over time - Susan Beebe

Hmm.. Come to think of it, actually I would first suggest that they get an IM account, and start connecting with their friends if they haven't even done that. All of us learned how to connect with our "inner-social circle" before we started exploring the "outer-social circle" right? - Winston Teo

I didn't Winston it just kinda happened it was using myspace and facebook before i ever IM'd anyone it's not till recent that i've started using IM's - Cecil Sandus

MySpace. They are probably looking to get laid so... - Hao Chen

They should join the one where their friends are at - Mike Doeff

Facebook remains the best place to start. - Pierre-Philippe Martin via twhirl

FB ? is that serious advise ?? Duncun - how much time do you spend on FB comp'ed to FF or Twitter ? you may know more people you know on FB, but do you really have the 'social' element at FB space ?after all the users wants a social network, not something that is fade , just because all my friends are on it ! - Peter Dawson

facebook. Its the easiest to get started with. - hadleystern

I'd recommend going for a ride on a bicycle, going fishing, or a long walk in the woods. - Jason Wehmhoener

Duncan's right FB 4 sure - Shey

none. not before they figure out what they want to do online. are they interested in finding people? probably facebook. conversation? maybe friendfeed, twitter. photography/video? perhaps flickr or youtube. etc. depends entirely on their goals. if they join something and it's not what they are looking for they may get discouraged and be reluctant to enter the space again. - Jamie Allen

I wouldn't recommend Facebook. It's ugly, confusing, cluttered and intimidating. I only have an account because it's a good way to find people I'd lost touch with (or rather, I let them find me and then I get their email address so we can converse OUTSIDE of Facebook). I am not a fan if you can tell. - Lindsay is :)

Friendfeed - Todd Jordan

technorati-- geeeeeeee.. could not resist .. :)_ - Peter Dawson

Friendfeed. If they aren't very social, Twitter - Chacha102 via twhirl

@Lindsay Donaghe: probably won't change your mind, but facebook has a new face - http://www.new.facebook.com/ - Jamie Allen

I wouldn't recommend FriendFeed on a first go. FF with other presences online is much more fun. I would recommend Facebook first - as much as I hate that, but it's the easiest to get a hang of if you haven't done any social networking online before.. - embee