Coffee: I really enjoy Starbucks Arabian Mocha Sanani (Arabian Mocha Java is better, but no available in the US anymore). It has fresh notes of dark chocolate, a richness that a lot of coffees miss, including many of Starbucks' coffees. This is my favorite "can be commonly found" coffee.
I also really enjoy Kona coffees. Kona beans depending on how they are roasted have a creamy taste. The favor of it varies greatly too I have notice. Some times it almost has a caramel flavor to it, also it can have a very natural earthy taste. They are really good to try, but a little bit harder to find where I live.
Yarn: Now this one is really a lot harder. I really love too many to count... Number one is Knit Picks Essentials. I am working on a pair of socks with it right now and I swear that it is so soft and the sock feels like there is nothing on your foot. The colors I have seen are also something else. I am using Spruce Kettle Dyed and if you look very closely there is a slightly mottled effect to the yarn, but it is really not at all noticeable in the sock.
I also love Malabrigo... This is one of the squishiest yarns I have ever worked with. Not only is the yarn so soft you just want to curl up in a ball and sleep on top of it, in it and all around it, when you finish your project the texture of the FO is squishy and warm and just all around a pleasure to be around. I made a scarf with it and not only did it keep my neck warm, it is so scooshy it feels amazing around my neck (not normally a huge fan of 100% wool on my upper body).
I think those are my two current favorites, but that is subject to change anytime I CO for a project with something different.