I LOvE them and usually drink at least 1 daily

  I don't eat meat so they give me the much needed protein that I find difficult getting in daily.  I usually use the EAS Myoplex Lite chocolate and vanilla.  I throw a banana, milk and juice in there.  For the chocolate one only a banana and milk.  They taste pretty yummy if you are into the flavor of powdered shakes.  Takes some getting use to for some people though. They average less than 200 calories a shake and give me 25 grams of protein and only 12 carbs so they are awesome for my goals.  
I also buy the already mixed 4 packs.  I usually try to slam at least 2/3 of one before my workout in the morning.  They only have approx. 110 calories and lots of protein and only 2 carbs.  They are also great for an afternoon stack when you get that oh so terrible chocolate craving

  Throw a piece of fruit with it and you have everything you need for a 4th meal in the afternoon
 
I would take a look at your goals, both diet and workout and then do some label analyzing and figure out what ones are best for you
 
By the way, GNC usually has their 10% off the 1st  7 days of the month for Gold Club members.  I find their prices the best on EAS stuff here in Colorado

 Not sure if you have one where you are. 
Also, be careful of the EAS pre-made shakes in the grocery store. They are different and lower quality tasting than the ones you'll get at a health store or vitamin store.  They look similar but have different sub-brand names.  The ones I like are the AdvantEdge I think and the powder packets are the Myoplex LIte.  
Hope this helps
  
-Pammer