I am the same way, I get distracted way too easily. I usually order whatever prints I like, and still need to get more solids. Fall colors are going to be very popular soon, and from what I have read purple, grey, and icy blue tones are going to be big this fall/winter.
Sorry I can't be more helpful, I'm too new to this to say what a constant popular color would be, I'd hate to steer you wrong.
I forgot to add about where to get ribbon. I have only ordered from a few places so far so can't say what some of the place's quality is like, but I like hairbowcenter, they are good, and I love the ribbon I got from them (their moonstitch ad is taunting me right now haha). Not sure what brand it is they carry. I have also ordered from UB, and like others have mentioned it is thinner ribbon but I do like it. I've not tried to make a bow with their wider ribbon though so not sure how that is. I've ordered from the HG store and the ribbon there is great, as is Ribbon Heaven, I need to order more but hoping to see more turkey ribbon first!
Other than that there is the ribbon retreat, ribbon carnival, really reasonable ribbon (that's who I'd like to order from next). There are so many others...check the sticky threads in the supplies forum, there's a ribbon supplier list there and it's going to be a lot better than me trying to use my faulty memory lol.