One more thing, if you're peckish on Plaza Salvador grab a cone of fried fish (the fish place also has cheaper beer than the bars and far cleaner toilets).
The Peruvian-Japanese near Alameda is called Nikkei (calle Caltrava). The solomillo there is amazing! Nazca is another lovely Peruvian-japanese restaurant (calle Baños).
As others have mentioned, Rinconcillo is worth a visit. It's the oldest bar in Seville and the food's pretty good. Bodega Santa Cruz is good if you want a traditional tapas bar near the Cathedral. The food is not the best but the atmosphere is great. Be wary of most places that are very near the...