My friend and I decided to visit Key West because we didn't have a lot of time to spare and we just really wanted to relax, eat (a lot) and be able to explore a bit during the day on foot. We knew going into it that Key West wasn't known for their beaches, so we chose to stay in a resort, which included one of best (and private) beaches in Key West and an adults only pool! We didn't plan to spend our nights on Duval street, so after long days of walking and biking around the island, pampering ourselves late evening poolside with a margarita was more than ideal. We stayed at the Waldorf Astoria and it was absolutely beautiful. All water activities such as kayaking and paddle boarding were included and there were plenty of chairs and hammocks, which you didn't have to reserve the night before. This wasn't the cheapest of the options, but it was worth it and if you monitor the room rate drops for a few weeks prior to your stay on Hotel Tonight, you will be guaranteed a deal!
As far as daily activities go, I've listed my favorite restaurants and beaches (and a little shopping in between). And, you can check off all of these spots in just one day:
Breakfast: Banana Cafe Rooftop patio was a plus!
Beach: Lagerheads Small, low key beach w/ a bar and food options. Or, you can head to the Fort Zachary Beach where most of the locals go (no alcohol allowed, $6 entry fee). Neither one of these options are touristy, but if you are looking for a beach that has more action, I recommend Smathers Beach.
Shopping: Key West Sunshine Club Great selection of swimsuits and summer gear!
Lunch: Blue Haven Adorable jungle-like atmosphere w/ the option to play ping pong! (across the street from Key West Sunshine Club).
Dinner: Santiago-Bodega Must get the Sangria and sit on their patio! Get there early to take advantage of the $5 happy hour tapas and 1/2 off Sangria from 3-6 pm daily.
Dessert: Better Than Sex This is a dessert only place. Best for a date and its fun to sit side by side and scroll through sexy dessert options on an ipad in the dark (Cookie Nookie Pie?)!