La Parte Vieja
Hazea - This is a good place to start your pintxo experience. You have to try a “guilda” since it is considered to be the original pintxo of the Basque country. The “brick de bacalao” should also be had. Goiz-Argi - Definitely top 3 on my list. The staple here is the “brocheta de gambas”. This may also be “the” best pintxo in the entire city. There are other good pintxos, but the brocheta cannot be missed. The owners are some of the nicest people around.
Ganbara - This bar is ludicrous. The décor should tip you off...mushrooms abound here and for good reason. The hongos a la plancha are insane, don’t fear the yema (egg yolk) that is served with it. The little bocatas de jamon are amazing too. Not a cheap spot, but definitely one of the best. Bar Nestor - Nestor and his brother own this place and they are a pretty cool duo. Order up a mug of Lowenbrau and a racion de jamon and some tomates. The ham here is incredible and the tomatoes are served with a little salt, olive oil and vinager...simple yet good. If you want to just have dinner here, order a chuleton to share and you will not be disappointed.
Bar Sport - This is a classic. Very consistent and you can count on it. When other bars are closed (which happens often), Bar Sport comes through and stays open late. Order a bottle of Sidra here and share it with your friends. Just make sure you know how to pour the stuff before you make a fool of yourself. I like the bolas de carne here.
A Fuego Negro - A modern and young pintxo bar. Its only been open for about 4 years now. This place is
always putting something new and interesting out. The menu is always changing here so I don’t have any recommendations other then to go here and try something crazy. You will not be disappointed. I know Ian definitely recommends the loaf of foie. Zeruko - Another modern place that is always pushing the envelope and coming up with new stuff. Definitely interesting. I don’t remember the names of the pintxos I had here but I know one came out on a personal sized grill smoking, and sizzling and another came out in a shot glass that was bubbling over with a white fog...good times.
Iturrioz - Another very well lit place. This one is on Calle Aldamar. Some very nice people work here. Try the “chupa-chups,” they are small and fun. The tosta de jamon is really good too as well as the tomate seco right off the bar. La Cuchara de San Telmo-Astelena -

El Centro
San Marcial - If you do finally venture out of La Parte Vieja, this place has great “gavillas.” It is on your way to “Buen Pastor” which is a great spot at any time of day.

Gros
Bergara - If you are near this place, you won’t miss it because it is extremely well lit. Try a “txalupa” or an “itxaso”... Senra - Senra is very close to Begara so you might as well hit both of these in succession. In my humble opinion this place has the best croquetas in town. My favorite is the croqueta de changurro.
Mil Catas - I’m not too familiar with this place but I know it is popular and it has great foie and lots of vino here. Patio Ramantxo - A little closer to the river and Kursal, this place has some good eats.

Bars/Discos
Bar Txiki - have a cana here before you head to dinner. It’s a small heavy metal bar with a great atmosphere. It’s great for having a beer on the street and people watching. Sariketa - Great spot after dinner between 11 and 2 am. All kinds of music...look for “my boys” dancing in the corner.
Etxe Kalte - Go here after Sariketa closes if you want to keep partying. You won’t find too many tourists here so your chances of falling in love are not good, but I guarantee a good time. It is a Jazz bar by definition, but it sure doesn’t seem like it at 3 AM. S N - This is a really fun place and usually full of a good mix of people. Chances of seeing a beautiful girl are pretty high.
Bar Kai - One of my favorite places to just hang out and have a cocktail. Great atmosphere and really good caiprinhas. Bataplan - Probably the most popular discoteca. This place will deliver a heavy dose of party if that is what you are looking for. I think it closes around 7:30 AM so this would be your last stop for the night.
Rotunda - Right next to Bataplan and similar in the drunken late night debauchery that it offers. Tas Tas/Be Bop/Molly Malones - Here are the touristy spots that serve their purpose. If you are looking to meet other travelers and women that speak English, these are the places to go. They are open late and can offer a memorable night out.