I'm Commander Shepard and this is my favorite series of all time !

If you've never played it, go for it.
If you have played it, but without its DLCs, go for it.
If you have played it with all DLCs, here's what you get from the Legendary Edition :
_ In ME1 : Usable weapons, variety in weapon types, unlocked progression and difficulty, improvements to Mako handling, ability to use ME3's default FemShep.
_ In all games : Upscaled textures, better lightning and reflections, borderless fullscreen compatibility, photo mode.
_ If you had the original games on Origin, I don't think I need to explain why being (almost) free of it is an upgrade.
_ Some bugs got fixed (most didn't, though).

I'm Commander Shepard and this is my favorite series of all time ! If you've never played it, go for it. If you have played it, but without its DLCs, go for it. If you have played it with all DLCs, here's what you get from the Legendary Edition : _ In ME1 : Usable weapons, variety in weapon types, unlocked progression and difficulty, improvements to Mako handling, ability to use ME3's default FemShep. _ In all games : Upscaled textures, better lightning and reflections, borderless fullscreen compatibility, photo mode. _ If you had the original games on Origin, I don't think I need to explain why being (almost) free of it is an upgrade. _ Some bugs got fixed (most didn't, though).