I've got a couple pair of antique Kum-A-Part cufflinks, and since I got them I haven't worn any others. Basically, instead of the standard cufflink style, they're symetrical, each half being held in the cuff like a button and then they snap together. That means you don't have to put them on after putting on the shirt, and they are easily fastened. Not that other cufflinks are that difficult to use, I just find this style more convenient all around.

That being said, I'd really like to get a pair of celtic knotwork links. But #1 on my list is a pair I saw a couple years ago, which may now be impossible to get. They had a black disk, around the face of which in silver was the Ring poem in Elvish from the Lord of the Rings.