I liked Wesley when I was younger just because he was a wish fulfillment character for me.
I don't hate him like some Trekkies do. Especially in season three he became much better written. But in season one, he's just too magically brilliant, and his behavior is not believable for a teenager. It would be one thing if he was only offering the occasional 'Think outside the box' ideas from his unique perspective, but in S1 he's better at everybody's job than they are and he thinks and behaves like a sheltered rich kid who's never met another person his age.
If they had made him as smart as he was but gave him a more believable personality for a teenager like Jake Sisko's it would be fine.