I somehow managed to go almost 2 years with one model of case on my iP6, a black/white Candyshell Grip. (Though it got replaced once after a year with the same exact thing).
Now seeing so many on sale I couldn't help myself and have four now. My OCD is going nuts and can't decide which to stick with.
Blue Candyshell Grip
Black/white Candyshell grip
Saddle Brown Apple leather case (love love love it but worried it's not enough protection, don't like the open bottom)
Orange/Blue Speck Mightyshell (love the matte back and grippy sides but it's a little wider than I like)
I wish Speck had this color combo in the 6/6S cases. Had one on my 5S and liked it the most of any I've ever had.