It's funny cos nearly all the "most feared" eyeshadows here (Freshwater, Carbon, Orange, Electric Eel, Beauty Marked, Bitter) are among my absolute favourites.... the first Mac look I ever did was Freshwater and Bitter, it was the brights that attracted me to the brand in the first place.... I used to be scared of Chrome Yellow as it drains me, but I've discovered I can rock it just fine if I wear it with other things....
The only pressed MAC shadows I'm scared of are Club and Cranberry. I am VERY attracted to both, but am afraid either would make me look like I've a black eye (I used to own Urban Decay "Lounge" which is very similar to Club, and was a horror beyond compare on me).... so dark reddish hued colours, basically....
The other thing I'm scared of (don't laugh, ladies!) is pigments !!!!! £15 for one eye colour is SUCH a big investment if I buy 'em from the MAC store.... and if I buy pigment samples anywhere else at all (Livejournal, ebay, etc) there's no guarantee they're genuine and I'm not putting horrible un eyesafe cr@p on my lids..... I think one day I may end up getting violet (as the looks shown on here always make it look beautiful and the pefect shimmer purple) or kitschmas (which I see as very multi-purpose and cute), but I've never been tempted thus far.....