In my opinion, I like them both, because they are the same person.
Shinichi is pretty cool IMO. In the beginning of the series, he was very into himself, but as the series progressed, he's still into himself, but not as much as he used to be. I feel like his current situation has made him reevaluate his life as a person. The one thing I don't like is that Shinichi can't cry. HE NEEDS TO LET OUT THE FEEEEEEELLLLSSSS!!!!!
And with Conan, I think he's downright adorable. I love the fact that he's always there for Ran whenever she needs someone. Also, I think it's sweet that he hangs with the Detective Boys and that he considers them friends even though his intellect is on a different level.