Many movies will still be displayed with black bars on top and bottom because their aspect ratio is different from most HD/LCD/Plasma TV's. You have to play a movie that has an actual 16:9 aspect ratio to get the fullscreen on your TV or zoom 21:9 to fill it. The 16:9 aspect ratio is designed to show 1.85:1 movies on most HD TV's and these are mostly shot on 35mm film. Newer films are shot in 2.35:1 (21:9) aspect ratio for ultra-widescreen and are shot on that aspect ratio for better viewing in theaters. Usually a film has two versions: a 16:9 for most HD televisions and 21:9 which is mostly for theater, you should choose movies that have the exact aspect ratio as your TV.
If the zoom function of the TV is skewed or distorted, it might be better to use the zoom function of your player. The quality of the picture size depends on the player's adjustment increments. Most BD players, specially samsung BD players have a fill screen function that automatically adjusts and zooms ultrawide movies to 16:9 hd TV's. Next time you should be critical in buying movies that are specified to be in 16:9 or 1.85:1 aspect ratio, this is usually indicated in the back. Hope this clears something!