There are a lot of Arabic words in Spanish, but I don't think there are so many ones used commonly, other than the ones James wrote. You'll probably find more Greek ones in daily conversation. An Arabic word with an interesting history is "assassin", but even in English you have:
coffee, candy, admiral, sugar (from Sanskrit), albatross, Las Vegas (thorugh Spanish), alcohol, safari, harem, matress, guitar (from Greek), aubergine (from Sanskrit), racket/racquet, arsenal, syrup, satin, amber, chess (from Sanskrit), divan, and other more technical like zircon, Aldebaran, algebra, algorithm, alchemy, or amalgam.
And don't forget the Germanic ones:
ropa, grupo, jabón, sopa, gris, balón, ganas, jardín, maleta, esquina, marcar, blanco, grabar, guardar, tarjeta, banco, brindar, forro, robar, bala, flanco, balcón, albergue, estafa, embalar, estampida, bono, tregua, desmayarse, bandido, banquete, adobar, vagón, sala, sacar, grapa, bote, agrupar, hacha, estampa, rampa, chapuza, garaje, espía, venda, etapa, rapar, bandera, atropellar, guisar, guerra, escote, banda, toldo, flotar, tachar, abandonar, falda, esquema, atacar, brecha...