Excluding some INTPc posters who are members here but post way less than I do, Costrin mostly. Aderack types my thoughts at times, but he kinda reminds me more of a friend of mine than myself, so maybe that's some of the familiarity. Talullah occasionally. (I find it easy to relate to a lot of the INTPs in general on here but not unusually so)
For non-INTPs, Evan's posts in the past have had a lot of familiarity for me, and heart at times too.
LOL Evan changed his type to INTP, so I'll add him to my list of same types.