Every 5 rated one is an anime that I could make through successfully and anything below a 5 is something either struggled with getting through or something I just didn't watch at all. Pretty simple.
I am against reviewing anime because I don't believe you should ever look at the reviews or listen to your friends or group or anyone whatsoever when looking into watching any anime. When you feel like watching a certain anime, regardless of what other people, decide for yourself if you'd like to watch it or not. For instance, I was told SAO was not the coolest anime like all the time all over the internet and by lots of people I know however, once I began watching it, I realized it was one of the favorite shows I have ever watched. No, it isn't my all time greatest but the matter of the fact is that I enjoyed it. I watch some pretty strange crap and I don't really care what you have to think because I personally rate things when or if I can get through the entire show. This is the only time when I might consider it but that is a huge might.
If you still can't bother to look at reviews, then just look at the star rating. anything rated above 4 is some what of a special type which has something that must be good to me and anything below seems to be a gamble however I have really found some really great low rated animes so don't get discouraged by ratings. Have fun.