OttomanScribe, Evilore and most mods in OT are lads you can share ideas with, even in the heat of an argument and still expect sane and well structured answers. Plus, they only seem to talk what they know about and don't try to make up stuff to look cool, that's really worth a positive mention on an internet forum.
Blablurn is unadultered fun: he never gets angry, is always joyful, and has a very equal mood overall. You can always expect to smile when reading him. My Swiss-GAF are equally nice and pleasant to talk with also.
Road, Mpl90, the_lascar, Chris1964, Nirolak, slaughterking, Aeana, Sammy Samasu, Corto Maltese, elektroplankton and many others are great contributors to sales-age as well. In recent times, because of the WiiU hardware speculation threads, blu and Thraktor emerged as real nice posters also.
And how could I forget Corky. This man, THIS GOLDEN MAN.
edit: Cheesemeister and Cornballer make the list too!