Searching for an app in the Play Store can be a bit of crap shoot, which is odd when it's run by a search company. Google just added a new filter to the web play Store that lets you restrict results to only those apps with 4 or more stars. That should clear out a lot of the junk.
The new filter is in a dropdown at the top of the screen when you limit searches to apps only (I mean apps generally, so games too). Just click the "4 stars +" option in the rating dropdown and you're done. Maybe more rating categories will be added later, but this is probably the most useful. I can't think of many instances I'd want to include apps that get less than 4 stars in a search.
There's no sign of this feature in the Android client, but maybe in a future version?