Hi Le Anne!
That's a great question! I guess it all comes down to your preference. You can get Magic Kingdom views in both the Contemporary Tower or Bay Lake Tower. Bay Lake Towers are villa styled, and much more spacious. If space is a premium for you, I'd go with Bay Lake Tower.
On the other hand, if you're looking to be closer to the action (monorail, shopping, arcade, etc.), I would consider the Contemporary. The Standard Rooms at Contemporary are also some of the largest rooms at all of the resorts, so you do feel like you have a little space here as well.
So, sounds like it comes down to comfort or convenience. For comfort, go with Bay Lake Towers; for convenience, stay at the Contemporary Tower.
Have fun will all your Disney planning!