I touched on this in the Marriott Marquis DC thread, but my ranking of Marriott hotels in DC region (with executive lounges!) are as follows, in order of best to worst;

1) Crystal Gateway Marriott; directly attached to Metro station with underground passageway, consistent suite upgrades, lounge has evening appetizers 7-days a week, one of best lounge breakfasts with omelette chef, renovated rooms, great water pressure
2) Georgetown Marriott; about 1/2 mile from nearest Metro, lounge has excellent evening appetizers (5-days a week) but poor desserts, very good breakfast (but no omelette chef), renovated rooms, exceptional water pressure
3) Marriott Marquis DC; about 3 blocks from nearest Metro, lounge has poor evening appetizers (5-days a week) but extensive dessert spread, average breakfast (no omelette chef), rooms not renovated but hotel is fairly new, poor water pressure
4) Crystal City Marriott at Reagan Airport; directly attached to Metro station with underground passageway, no room upgrades, one of the worst lounges, renovated rooms, decent water pressure