I've tried various LCD screen cleaners and most are no good, especially the gells (those smear horribly). The best LCD cleaner I've found is sold by a computer repair chain (Data Doctors). It's horribly overpriced but a little bit goes a long way.
Frequently rinsing out a microfiber cloth with hot water and letting it dry prevents smearing.
Even better than "canned air" is a blower. I have a DataVac Electric Duster. That blower is almost powerful enough to blow leaves (actually it could if one is a bit patient). No more replacing expensive cans of propellant driven gas nor worrying about escaping propellant damaging the screen. Although expensive upfront, it's much more economical in the long run. While safer and more economical than "canned air", the camera lens squeeze bulb just isn't practical for a large LCD. It would take forever to clean a large screen and just doesn't generate enough pressure for anything larger than a camera lens. I do keep one in my purse for dusting camera lenses and other small things.