I know what you mean. Order of popularity is based on how many downloads there are of a game not how good it is. Obviously many many more people are going to download the free one then the paid one.
Two ways around finding the paid for app.
1) In Market, in either the App or Games list (when you can see hte list of apps/downloads), press Menu - Change View and you can choose to just list the paid items and find your item there.
2) If there is a game/app you like and you want to pay for it, find the free/lite version and scroll down to "View More Applications" and this lists all apps by that developer, including the paid versions.
To leave comments, in Market click My Downloads, select the item you want, then you can give it how many stars you want and once you have rated it an option appears under your stars to Post a Comment.
Hope that helps.