Most of the action these days is at the Clarion downtown San Jose (Casino Amon, formerly Casino Paradiso). They have $2/5 NL every day starting at 3pm and on days that there are tournaments they will also usually have a $1/2 game. You can find a $1/2 NL game going every day at the Crown Plaza Hotel in Sabana (formerly the Coribici).
Depending on when you are here, there might be some decent tournaments. This site has info on (in Spanish) the "Costa Rica Holdem Championship" which is running through June:
http://www.bananapoker.net/inicio/index.php
Monday nights at the Clarion there is a 30,000 colone (~$55) buyin tournament at 8pm. It used to have a guaranteed prize pool but there was some issue with the organizer so I think it's just a regular freeze out now.
Thursdays at 8pm there is a 2,000,000 colone (~$3.7k) guaranteed 40,000 colone buyin (~$75) tournament at the Ramada Plaza Herradura Conference Center I believe. It's right next to this casino
http://www.thunderbirdresorts.com/in...herradura.aspx They usually end up with around 60 people from what I hear, but I haven't played that tournament myself. The LAPT was held there and its a very nice room. I believe that they also have cash games going after the tourney.
The White House game doesn't run any more, so $2/5 is probably the highest stakes you are going to be able to find. The games are soft, but there are some good regulars. You should be able to figure out who they are pretty quick. I have never seen anything shady in the cash games aside from some uncommon soft playing in the $1/2 games between regs. All of the dealers should announce the action in both Spanish and English, and also speak English fairly well.
One nice thing about the games here is that you can generally live straddle from any position and for any amount, with unlimited restraddles. Some casinos only allow UTG and button "Mississippi" straddles, but most are any position. This can really loosen up the game and get some great action going.
Of course like in any casino you want to pay attention to who is around. If you are cashing out a fair amount of money make sure there isn't anyone watching you closely. Also be sure that nobody follows you out of the casino and don't be afraid to ask for a security escort to your car if you feel it is necessary. Be wary of anyone who tries to befriend you in a shady way, especially if they aren't playing themselves.
It is very important to have your passport with you, or a photocopy of the front picture page as well as the page that has your entrance stamp (clearly readable too. a good idea is to photocopy the front page before you come and have the immigration officer stamp the back of the photocopy as well as your actual passport). If for whatever reason you get pulled over and don't have this, and the cops can tell you are a clueless gringo, you will probably be extorted for all the cash you have on you. As long as you have proof that you are in the country legitimately and you aren't drunk they can't really do anything.
A lot of the cops speak English and will generally be willing to work something out if there are any issues. Typically $40 will be enough to take care of any problems, and anything more than $100 and you're getting taken for a ride. The worst thing that can happen is for the cops to know that you have a lot of cash on you. Don't keep it in your pockets/socks or any place obvious in the car like the glove box. Inevitably they will find some problem that requires a big 'ticket' if they know you have cash to pay them off.
Feel free to PM me if you have any questions.