I only have four products that I will automatically repurchase, although having said that I haven't yet repurchased my Nars lip pencil.
My repurchase products are:
Nars Sex Machine Velvet Matte lip pencil - I wore this on my wedding day, it's a beautiful, natural color on me.MAC Syrup lipstick - I'm not trying to use this up so it's unlikely that I'll finish it this year, but if I do I'll get another one with B2M.
Chantecaille Camellia Lip Chic - This is the lipstick I'm working on finishing at the moment. It's one of my all time favorite lipsticks and my favorite lipstick formula. A definite repurchase.
Chanel Boy Rouge Coco Shine - Tiger bought this for me on the day that I had Chai, so it has sentimental value for me. Once I've finished my Camellia Lip Chic I'll be working on finishing this.