The best option I've found for cleaning mirrors, windows, glass-topped tables, etc., is a microfiber cloth.
You can buy a package of 2 that are specifially for glass at Wal-Mart for $1.97.
Just wet one with plain water, wring out thoroughly and wipe. Give it a minute to dry. No streaks – no chemicals – put the cloths in the washer and dryer and you're ready to go again.
They're great for stainless steel appliances, granite countertops, the list is endless!