I prefer watching movies and ovas, nowadays due to work, so groups like Thora, KickassAnime are my faves. But any group that released something I wanted to watch, have my thanks.
I personally like Eclipse's subs. They are so professional and I have never noticed a mistake in any of their releases. But too bad they're hibernating right now, hope they return sometime soon!
Well since it's been years since I last actively watched Anime I'd have to say Dattebayo is the best I've seen. Well encoded, easy to read subtitles, accurate subtititles and not to mention a great Kareoke system that I never really cared about but that gave it all that little extra.
