increasing english vocabulary

What do you guys think the best method of increasing english vocabulary would be for man who, according to test from testyourvocab.com knows about ~5.5k words. I'm not native speaker of course. I don't talk to natives neither. Grammar isn't my best ability, cuz I rarely write in English, although I read and listen a lot. My only problem is that I don't understand some words when I read or listen. Sometimes I can guess the meaning but next time when this word shows up I don't remember it and I need a while to get what it means. My conclusion is that it's not a good method. It's too slow. How to increase my vocabulary efficiently? Any ideas? Already I'm using sort of program-reminder - Anki which tells me when to repeat a word, but I need to enter it manually and variety of these words depends on what i watch or read. Sometimes these words are important (in my opinion, commonly used) and next are used really seldom, but I reapeat them too. Could learn more important words instead. So thats probably not efficiently method either...
PS I do love read and listen to english. Especially old calssic movies and anime stuff. Maybe do you recommend some to learn English from them?
And If u could please mark major mistakes made by me in this post...I would be greatful.
Cya and thanks in advance.