anything that purports to tell you if you're related to Cleopatra is meaningless. (You don't actually get DNA from all your ancestors, some gets crowded out).
The best ones to use are the ones with the biggest databases as they have more samples to draw on and compare yours with. Ancestry ones are supposed to be good.
BritainsDNA made the claim that Prince William had Indian ancestry. They make some very unusual claims and I wouldn't personally give them my money
https://www.theguardian.com/science/blog/2013/feb/25/viking-ancestors-astrology
These people have a good reputation
http://www.oxfordancestors.com/
IT's hard to recommend anyone unreservedly; a bit of guesswork goes into all DNA tests and none can be guaranteed correct. But at least a reputable company will give you a "best guess".