If the distance from Legoland doesn't bother you, than I think that the Grand Del Mar is a fantastic choice - one of my favorites in the area.

They also have a couple of great Virtuoso promotions running right now.

There are also very spacious villas at the Grand, but unless you need something bigger than the FS Aviara Residences they're probably overkill (and much more expensive than a timeshare rental).