I use Sony LCD cleaner gel/spray. It doesn't smudge and works well on the iMac, PC Laptops and our LCD TV. Not cheap, about $40.00 for a 250ml spray bottle but you don't use that much as it comes out in a very fine mist. We've had the same bottle for 3 years and it's about half full... or half empty if you are solely a PC user!! 😀