I have the knitpicks and have been less than impressed. I've had to send bits back for replacement way too often. I have also heard that the Addis can tarnish and pit. My personal choice after trying the other two is Boye Interchangeable, they have a nice sharp point, about like knitpicks, maybe sharper, but not much. People have complained about the cables being stiff, I don't mind them and for magic loop I used the "hack' from Craftsters.
and that works really well. There is a person selling the finished 'hack' cables at an etsy shop on Ravelry for a reasonable price. I did the 'hack' myself and it was fun and easy.
I don't have a "joanne's or Michaels near me but have heard you can get them reasonably with their discount coupon. It works out to about 30 or 40 dollars or so I've been told.
Another thing to think about is the length of the needles you like to work with. I have a problem with short ( 4") needles as my hand pushes on the cable where it joins the needle and I have broken one of my knitpicks at this join. I was able to fix it myself but when I bought the Boye needles I got the older set with the metal that bends at that point. Now the needles just fit my hand as if made for me. Other people have complained about the bend in the cables as a problem for them when joining two or more cables together for larger projects. I simply use the 'hack' cables and have no complaint. The older set, with the bend, comes in a brown case and the newer one (without the bend) comes in a red case. I now have one of each and love them.
I have been thinking of offering a new set of Denise in trade for an older (Brown) set of Boye for my daughter, she really likes my sets and I'm not giving them up. I bought the Denise and tried them once and tried to take them back but the yarn shop was going out of business and wouldn't take them.
Hope you find just the right fit for you. Can you visit a local yarn shop and just sit and try some? That might be the best idea.