Your best bet for downtown is here:
http://www.hotelsolamar.com/
Same price range and swanky hipness as the W if that is what you want, but it is actually in the Gaslamp quarter so you can walk to everything: Bars, restaurants, late night clubs, grab a peda-cab or cab to seaport village, the zoo and the trolley runs right through downtown if you want to take it to old town, mission valley, or down to Tijuana. You can see the outfield of Petco Park (which is a block away) from the rooftop J-Bar on the 4rth floor and can come and go as you want as a guest without waiting in line.
The W is nice, but it is much more of a walk to get to the Gaslamp Quarter.
If you want romance and seclusion go for the Hotel Del Coronado... but be prepared to drive to everything else.
If you prefer the La Jolla area then I would recommend La Valencia or the Hotel Parisi right in the heart of the village, they are across the street from each other surrounded by shops, restaurants and La Jolla Cove.
If you want the most bang for the buck, centrally located to Downtown and the beaches then try the Best Western Hacienda in Old Town.
Hope this helps and good luck on a week or two successful consummation.
