Puzzles in DDO (Excluding must stand on x and y or pull x and y at the same time)
Master Mind
This puzzle is seen in the Reaver's Fate Raid and while there is a solver to help players because of the 4 slots with 6 possible there is no real way to memorize the puzzle itself so this is more a element of deduction and not a memory. Additionally, this is made harder as you have a timer as well as mobs that can knock you around if not dealt with.
Deduction Puzzle (Riddles)
Found in The Crucible in Gianthold. This is the puzzle with six doors and you need to guess which door the horn is behind. Granted most people simply pick the same door over and over again until it is the right door, there is a way to solve this. If your wisdom is very low you will get DM text across the screen telling you which door the horn is in something like 10 or below wisdom. But that is also not possible for many players as tomes actually hurt us as it brings our wisdom up. But what people miss out on is that it gives you clues - Up to 3 which you can use to figure out which door you need to open. Of course the door numbers are on the floor and in Roman Numerals
Another that fits this is Demon Queen Pre Raid with the puzzle of Six Swords. There is actually a pattern to the solution, now because it is only Six slots and with the knowledge of what is First and what is last you are really only solving 4 slots with 4 possibilities of which you know that the first line indicates the first slot of the 4 is one of the two mentioned meaning etc. So again we only have a page outlining all possible solutions because there is only a finite of possible solutions.
Another that also fits here is Litany of the Dead. This one has 4 solutions and there are guides on how to answer to open up the path that you want. However, all of these questions can be answered if you actually read the NPC text and story lines and gain a little understanding of each boss as well as understanding Alignment in the DnD universe.
Lights out puzzles 3x3, 4x4, 5x5 and Circle
These are pattern puzzles really not much you can do except memorize a solve philosophy and look for a pattern not much different then solving a rubics cube.
These are seen in The Pit (Original location), Shroud, and Demon Web Trial by Fury
The more unique ones are the ones that are not Squares but are lights on the floor like Monastery of the Scorpion, the solution takes a little more then a single method and even with a solver it can become difficult as mobs run over sections. This particular one not only needs patience it needs support from other party members to control the mobs.
Another similar puzzle can be found in Enter the Kobold where you are ported around in a pattern much like a knight on a chess board. While one could memorize a pattern to get the whole board, most just keep going until it is all lit up.
Light Path Tiles
This is where you turn a tile to light a path. These are memorization puzzles and they are found in quests like Twilight Forge (Green Room), Ghost of a Chance, The Scoundrel's Run, Cannieth Challenges the ones where you are in the Manner, Delirium, VoN5 and more - This is probably one of the more used puzzle types. While the Mirrors in Deathwyrm are a different take, they are similar in nature to this type.
Wheel Puzzles
6 symbols on a wheel with the solutions scattered in the dungeon where the puzzle is. Seen in The Pit, Haywires Foundry, The Crucible, Under the Big top and a few other places. One of my favorite places this can be found is in Schemes of the Enemy - Solve a puzzle to unlock a door and also in the end fight if you solve the puzzle it depowers the teleporting defense system making it easier to kill as it is not porting during that time. It is a swell way to make this last fight a far cry easier then many make it.
Maze
Mazes could be something as simple as the Gates in Maze of Madness or Complex like the areas most groups skip in Deathwyrm. Other places that utilize maze The Crucible and Prey on the Hunter.
Personally I would like to see more puzzles like Master mind and deduction (Riddle) based on in game dialog. It would be even cooler if such puzzles (riddles) were based on different perception skills, such as Search, Spot, and Listen or even would be something that with strategy you can discover such as if you sneak and are not spotted you get to overhear a conversation or when you rescue an NPC in a room Such as in Chains of Flame with the dwarf they give you knowledge you will need to proceed.