I prefer the digital ones- in my opinion they are worth the money, as it gives you a clear answer either way (as opposed to trying to interpret those stupid lines). I know a lot of people who have gotten false positives (evaporation lines) on the dollar store ones, and the First Response tests gave me barely noticeable lines when I was getting positives with the digital. I also really don't like the Life brand ones that are available in some drug stores- I have used them 3 times previously, and in all cases I didn't even get a control line.
I found a bunch of digitals onsale at the drug store (Clearblue Easy)- but if you find them too expensive, the Equate brand from Walmart is inexpensive and also works well.

- when I thought I was pregnant I went out and bought a bunch of different brands, JUST to make sure of the response.
There is a website that outlines the sensitivity of different tests:
http://www.peeonastick.com/hpts.html