I have two suggestions:
When I am looking at the ratings that were given to a certain movie (such as
this page), then the usernames of users with a personal page are clickable, linking to the personal page (for instance to
this page). When I am browsing the ratings though, and someone gives a rating that stands out, I am interested how this rating compares to the other ratings this user has given, and not in seeing his personal page. I think it would therefore be better if clicking on the username (when browsing ratings) would link to the page with all of the user's ratings (such as
this page (I think the "movies rated by this used"-tab should be the first tab btw, rather than the summary)).
My second suggestion is pretty old, I've suggested it (not publically) back when the player point system was first introduced, but it never really gained any traction. I think it would be neat if every day, a snapshot of every user's number of player points was taken and saved somewhere. This way, you can generate a graph at the end of the year of a player's progression during that year. If a player had a lot of publications that year, or movies that were obsoleted etc. Think it would be interesting :)