Thanks to all who participated in the poll and post votes! In the end the threads didn't get many votes in order to do a proper comparison, but we must work with what we have. Due to the low amount of post votes in the threads I wasn't able to do a comparison between the post and the poll votes.
Max post votes were obtained by the PS3 with 8 posts, next the Wii with 5 and then both Xbox 360 and DS had 2 posts. Meanwhile in the polls the quantities were a little higher: PS3 (35), Wii (24), DS (12) and PSP (6).
I was hoping for at least 50 votes in order to get a good enough sample. You will notice that the handheld comparison is going to look weird, or the Wii results I obtained here are somewhat different to what I previously have.
Without any further ado, here are the Chartz
VGChartz Xbox 360 owners who bought the least first party titles are in the 0-20% range, PS3 closely follows them in the 21-40% range while the Wii owners just buy Nintendo software in the 81-100%. In handhelds, the average PSP owners bought mostly third party titles although a few of them purchased mainly first party games, and for the DS viceversa.