For the love of all that is Holy, I swear this thread get started at LEAST once a month? If you are really interested in what people want you can see 4 zillion posts by a simple use of the SEARCH function. Let me assist... these are only a Tip of the iceberg..
Here: New Monsters for Future Expansions
Here: New Monsters in Game
here: New Content Ideas: Monsters you'd like to see
Here: Most Wanted Monsters
Here: Top 5 New Monsters You'd Like to see in DDO
Here: What DDO Mobs would you like to see?
Here: Things i would like to see in the game
Here: Dante's Big List of Suggestions
Here: Enough undead. how bout some real monsters
Here: Monster Mesh
Is it Friday yet?