Don't get me wrong. Cancun was awesome, and the service at the resort was probably some of the best I've ever had. But I went with a rich friend of mine and somehow ended up blowing through about 1,500 bucks in under a week at what should have been basically a free vacation. Oh, one more thing to mention with that is they completely bait and switch you if you're trying to rent a car there. What was supposed to be a cheap car rental basically ended up costing me almost 200 more after I was told they had to buy Mexican insurance. And they started haggling at $400 extra so you know it was a sham. Getting around there is also fairly easy, but you WILL get stopped as an American driving a rental car, so make sure you don't have anything on you, and even if you're clean, I was told by the hosts at the resort that most of the local cops will require a bribe before they let you go. That's just hearsay though, so don't take that as gospel.
The Best Western Jaco is literally built on the beach. Jaco USED to be a major surf destination, but apparently the big waves have moved down the coast a bit, so you now have just a gorgeous, unspoiled stretch of white sand. They have three bars there and the main one we spent time at is maybe 5 steps from the sand. It's on the Pacific side, but if you want to head over to the Caribbean for a day trip, it's a fairly easy drive. Concerning driving there, I actually would recommend NOT getting the upgraded car-you want a manual transmission just because some of the roads can be pretty steep. Concerning the food, it sounds a little off-putting from the description, but you can get food whenever you want. They just have their main mealtimes (breakfast, lunch, dinner) and then have snacks set out at all hours like burgers, hot dogs, chicken tenders, that sort of thing. I've only been to a handful of all inclusives, but that seems to be pretty much the standard. I'm a 3 plates minimum at the buffet kind of guy and I never went hungry there. The food is nothing special, but it's decent enough. You can get some pretty great street food at little markets and such for cheap on your day trips though. We usually do fishing charters and you can just take your catch to pretty much any local restaurant and get one of the best seafood meals of your life too. I'd recommend a group called Quepos fishing adventures if that's something you'd be interested in. You can usually get them down to a few hundred bucks for a full day charter and they really know their shit.
Oh, just an FYI, it does help to know at least a bit of Spanish, but it is in no way required, especially on the resort where everyone speaks English. I'm starting to sound like a shill for CR, but it really is one of my favorite quick vacations.
Quick edit:
Hotel Best Western Jacó Beach in Costa Rica the website for the hotel. I know Best Western doesn't sound like a luxury joint, and it's not, but it's definitely a lot better than you think of when you hear best western.