This is a great site, thanks Madridman! We took the suggestion for Restaurante Platero and it is great! Ramon is a warm and inviting host, told us more that once he wanted his restaurant to be "su casa". Wonderful meal at a great price. Will definitely go back and highly recommend to all.
Right off the Puerto del Sol, down the sidestreet Espoz y Mina. Very easy to get to if you're staying at Hostal Peral, which we did.
I printed off the previous recommendation and brought it with me to give to Ramon - he enjoyed seeing it.
Another find is Salmon Do. Off the c/De Las Huertes on c/Leon. Excellent meal there, too. But for warmth and a wonderful host, Restaurante Platero is the best!