When they're good, nachos are (for me, anyway) one of the ultimate bar snacks. At their most basic, nachos are corn tortilla chips covered with melted grated cheese and salsa. Many places make elaborate versions of this Tex-Mex snack that include refried beans, guacamole, sour cream and sliced pickled jalapeno chillies. I've even seen (but not tasted) nachos with crab meat. Haute cuisine it's not, but it's a snack that does its job - giving you something that's easy to eat while sipping a cold drink.
Most of the time, nachos are made of tortilla chips out of a bag, which is fine, as long as it's a good brand and they're fresh. The chips should be seasoned only with salt - please don't use "nacho cheese flavoured tortilla chips" (which admittedly, are rather addictive on their own). The tortillas and grated cheese should be heated until the cheese melts before adding the guacamole and sour cream. The best versions are made with tortilla chips that are freshly fried and salted before the toppings are added. Too few places pay attention to layering the ingredients; it's annoying when you get some chips that have an abundance of topping while others have none.