Misty definetly...She likes him and he likes her, it was made clear in Gotta Catch Ya Later.
Not really. "Gotta Catch Ya Later" made it clear that Misty has romantic feelings for Ash. However, Ash's feelings for Misty continued to remain ambiguous.
Throughout the series, Ash has not given a clear cut indication of viewing Misty in a romantic sense. All of the "evidence" on his side of Pokeshipping can easily be disputed. However, Misty's crush on Ash is as solid as they come. Overall, Pokeshipping is an unrequited romance. 4Kids may support it, but that does not mean squat in the end. What the Japanese writers say go, not 4Kids.
One-sidedness aside, they make a lousy couple. Both are short-tempered and stubborn people who are quite aggressive and domineering. If they were to get together, they would no doubt have a constant power struggle between them. Imagine them married with children arguing with one another on a twenty four/seven basis. Love to see that picture >_>
Personally, I would rather see Misty with Tracey, since his calm and mature demeanor nicely balances her fiery personality.
I do not mind Ash with May, since (unlike with Ash and Misty) their personalities actually do complement each other rather well. However, because they do not share any chemistry between them, I doubt they will get together. They are just platonic friends. If anything, May is most likely to end up with Drew, considering how blatant Contestshipping was made in the show.
I have not seen much of the Sinnoh saga, but Ash and Dawn strike me as having an older brother/younger sister and student/teacher relationship. Penguinshipping seems more likely to me. However, like with Advanceshipping, I do not mind Pearlshipping. I just cannot see it transpiring in the show.
So, if Ash will not choose any of the girls he has traveled with to be his romantic partner, who will it be? The answer to that is simple.
Pikachu