A few of my favorite bites gathered from my year abroad in Barcelona...
Estrella Damm Beer - this beer is served in all Catalan bars and has been brewed in Barcelona since 1876 http://www.estrelladamm.com/
Serpis - Anchoa olives - you will find these in every single bar in Spain. They are the perfect accompaniment to cerveza and vino
http://www.serpis.com/english/productos_aceitunas_anchoa_mrellenas.html
Manchego Cheese - sheeps milk cheese made in the La Mancha region of Spain from the Manchega breed of Sheep http://www.cheesefromspain.com/CFS/1505Manchego_I.htmhttp://www.deandeluca.com/cheese/manchego-and-membrillo.aspx?ref_code=GoogleMerchant
Membrillo - a sweet spread that goes perfect with cheese or on toast in the morning and is usually made with QuinceHere is a recipe you can make at home
http://simplyrecipes.com/recipes/membrillo_quince_paste/
or if you just feel like buying some...
http://www.gourmet-food.com/gourmet-food/membrillo-quince-paste-102205.aspx
Iberico or Jamon Iberico de Bellota - this is the most amazing cured ham you will ever taste.This is considered a delicacy especially in the US where it is mostly illegal to import. I would almost say this is the Spanish version of Italian prosciutto just so you get the idea of what it looks and tastes like except Jamon is a million times better and therefore expensive to buy but worth it http://www.jamon.com/iberico.htmlhttp://www.tienda.com/
Atun - also called Bonito del Norte. In Spain most of the tuna comes packaged in olive oil which is usually served by itself on fresh baked bread and is now what I prefer over regular tuna in water
http://www.amazon.com/Bonito-Del-Norte-White-Olive/dp/B000EFIJSQhttp://en.wikipedia.org/wiki/Bonito
Piquillo Peppers filled with Goat Cheese
http://www.marthastewart.com/338102/stuffed-piquillo-peppers-with-goat-chees
Spanish Chorizo
http://www.igourmet.com/shoppe/prodview.aspx?prod=300&src=froogle
Spanish Tortilla with Eggs and Potatoes
http://www.foodnetwork.com/recipes/tylers-ultimate/spanish-tortilla-recipe/index.html
Thick Hot Chocolate and Churros
http://www.amazon.com/Valor-Taza-Thick-Hot-Chocolate/dp/B001KYLJ6E http://www.foodnetwork.com/recipes/claire-robinson/churros-with-chocolate-recipe/index.html