Personnaly, I would wait until you got there to request the room, with a standard reservation. We've always had standard reservations (I guess twice counts as always) and each time it was upgraded to garden. As for a particular room, our favorite was 5111 (South Wing, close to tower, 1st floor). This is the way the room numbers break down
1st digit - 5 - south wing, close to tower
- 6 - south wing, far from tower
- 7 - north wing, close to tower
- 8 - north wing, far from tower
2nd digit - room floor
3rd & 4th digit - room number
Hope this helps. Enjoy.