Best value in the Gaslamp District
When you first look at the Ramada Historic St. James Hotel in the Gaslamp District, you may think, "Yeesh". But this hotel has almost everything you need for a business trip, or a weekend of partying in the Gaslamp. It is in the heart of the Gaslamp, but I have never been kept up by the noise of the street. Great value, amazing service, and perfect location. Add in a free airport shuttle and free wi-fi, and I can't see spending double the price to stay a couple blocks away. Also, be sure to go up to the roof-top deck. A gorgeous view of downtown makes for a great place to have a few drinks and relax!
A couple of important things to know/note: The rooms are small, but I have never spent less time in a room then when in SD. The beds are comfy and everything works. To say their elevators are "old school" is an understatement - the nearly 100 year old elevators still run at the same speed. You have to open the door and pull back the gate to get in. IMHO, it only adds to the charm of this hotel, but just don't be surprised. 
Only thing to look out for - As I said, there is some noise and clammor that goes on if you are close to the eleveators. If you are in for business or are not "night owls", make sure you request to be away from the lifts.