I think you can easily go either way. Just choose a yarn which has colors and a look you like. I think Lion Brand's Wool Ease is a wonderful acrylic/wool blend with some really nice colors, especially the heathered colors, and you can wash and dry it too. But, it can be slightly itchy because of the wool. If you are concerned about the itchiness, go with all acrylic. It washes and dries easily too, of course. I've used Lion's Jiffy acrylic yarn which is quite soft and nice, but it is a bulky yarn. There are lots of other nice yarns, I just happen to be most familiar with Lion.

Let us know what you decide.

I always use acrylic because I can't afford the Lion Brand specialty yarns. There are some supersoft varieties out there, you just have to look for them and feel them for softness.

As long as the yarn fits the guage for the pattern then you can use any type of yarn that you can afford. I have used Lion but really like Plymouth's Encore worsted wool, Manos del Uruguay Wool, and Rowan's Calmer. All make lovely afghans.

I like Simply Soft yarn I think it is Caron. It is really soft and easy to work with. Also not so heavy as some wools can be.