I like to take the firmest tofu I can find (this is usually vacuum-packed, not water-packed) and cut it into slices or little cubes, and then pan-fry it in olive oil with a splash of lemon juice added halfway through till it's golden-brown and chewy. Then I put it in pasta (cubes) or on sandwiches (slices) - the sandwich kind is especially nice with spinach sauteed with cheese and hummus.