If you absolutely must grind away to try to get better gear and a higher level in Destiny, and for some reason you don't want to play the things that are actually fun, you can simply stand in front of a cave and shoot at an endless stream of enemies for the next few hours in hopes of a legendary drop.
There's a cave on Old Russia that when positioned just right, you'll get yourself a nice steady stream of enemies who explode encoded engrams like sweet candy from a pinata. Here's the video on how to do it and where to go...but you better get there fast. My guess is Bungie fixes this in the next day or so.
UPDATE: This has now been patched and no longer works. For now, the only consistent/easy way to get legendary things is through the Queen's Wrath event that runs until Oct. 6.