I like both films, but I had to give my vote to Scream. After five NOES sequels, and only two of which were really any good, New Nightmare was a welcome change, but it was too little too late.
Scream, on the other hand, was a whole new take on horror films. Some parts were genuinely scary (the opening with Drew Barrymore for example) while others were deliberately kinda silly (pretty much any scene with Randy in it). As a whole, I enjoyed it just a little bit more than New Nightmare.