Personally, I'd recommend the use of Electrum over the others because it gives you more control and less reliance on a 3rd party. From what I've seen the Chrome app doesn't have many features and will be lacking if you've used something like Electrum in the past. I don't have experience with GreenAddress but you do lose some control as you are relying on their website to be functioning. Electrum ( with proper backups ) seems to be the best option to me.