There are a lot of great artists doing a lot of great things with their music, but a few names will be at the top of any list of the best trip hop artists out there.
The genre evolved from what some call post-acid house music, which you can see in the downtempo vibe it has carried on.
It is always tough to say who the best artists are in any genre, but some people definitely deserve recognition.
In no specific order (who am I to say who should get the top spot?), here are four names that you should definitely have added to your playlist:

• Portishead: It really can't be denied that Portishead was part of the vanguard of trip hop and if you helped define the genre, you better be on the list.
  That is why they are included here, but, of course, this band is so much more than that.
  In fact, even with the rise of so many competitors, they continue to break the mold at every turn.
  Fun fact: the band formed in Bristol, England, but took their name from a nearby town.
  
• Bonobo: This one is another Brit, Simon Green, who took the world by storm just as the millennium was shedding its skin.
  Not only is it obvious that each track is better than the next, but Bonobo deserves extra kudos for mixing and producing a lot of his work himself.
  In fact, Animal Magic (2001) was entirely self-produced and he performed most of the instrumentation too.
  
• Massive Attack: There must be something in the air in England, and especially in Bristol.
  Whereas Portishead helped create trip hop, many fans would argue that the guys from Massive Attack are trip hop.
  The duo has won so many awards that it's almost redundant to put them on a "best of" list, but then there is no justification for leaving them out, either.
  These guys have inspired their peers and the next generation.
  Pretty good for on lifetime.
  
• Hooverphonic: Okay, so this Belgian group has long passed the stage where you can call them pure trip hop artists.
  But isn't that the beauty of a true musician? Either way, they have been blowing away fans with their synthetic pop/rock sound since they first got together in 1995.
  Their longevity alone is a good sign that they have figured out how to make some pretty hot sounds.