I used to live in Miami and there was small chain market there called Gardner's Market. They had lots of nice quality, overpriced groceries but the real draw was the deli. You could pretty much take anything in the store back to the counter and they'd throw it in a sandwich and charge you like $8. Basically there were limitless possibilities and I was once made fun of by the lady making my sandwich for not getting more fillings.
I've spent many a weekend trying to find someplace similar in the area to no avail. Along the way, I've certainly found a lot of decent sandwiches so what I'm really after at this point is somewhere with quality meat, cheese, and fillings and either a TON of selection or somewhere that will allow extreme customization.