The short answer is to use song/search instead of artist/songs -- that will give you a lot more control over what you get back. To find the top three songs by song hotttness on Deezer for Radiohead (with track IDs), do:
http://developer.echonest.com/api/v4/song/search?api_key=XXXX&results=3&artist=radiohead&sort=song_hotttnesss-desc&bucket=tracks&bucket=id:deezer&limit=true
However, if what you're really trying to do is generate a good playlist for a genre, have you considered just using the playlist API? For example:
http://developer.echonest.com/api/v4/playlist/static?api_key=XXX&type=genre-radio&genre=abstract%20hip%20hop&genre_preset=core-best
Will give you a set of songs that serve as the canonical "intro" to Abstract Hip Hop.
-Eli