In my eyes there are six levels of intoxication. There are states above the six I am about to outline, but I consider those beyond intoxication -- the ones where you land in the hospital.
Level 1: Sober. It's probably not the way you want to be, but it works for most common chores such as working or raising a family. This is your base state, homeostasis. You may not like it but the average person spends more than 70% of their life completely sober.
Level 2: A quick drink. This is meeting a friends before class to grab a beer so you can make it through another calculus lecture. OK, maybe two beers.
Level 3: Family Events. This is the Christmas where you don't want to embarass yourself infront of Grandpa and Grandma, but you still manage to get down five beers before the night is up. A good start, but just enough to take the edge off of your annoying aunt.
Level 4: Standard night out. As implied, this is your usual night out. Usually accompanied by a cab or friend ride home -- on nights of lack of judgment, lack of money, or lack of friends, maybe not, but it's probably a good idea after 6 beers and a shot of tequilla.
Level 5: To get drunk. This is when you stop on the way to the bar or party to pick up a forty of cheap beer and slam it before going inside. Hell if it's a long ride maybe even pick up two. Upon arrival you avoid time wasters like hugs and hello to go straight for the alcohol -- which at this point is usually liquor since your stomach is already full of beer. The next morning you know you got home, but you aren't really sure how. Some clothes may be missing, and your wallet is short $30 from the lemon drops you bought the group of ladies accross the bar.
Level 6: Intoxication. This is drinking beer in the shower while you're getting ready. You know the night is going to be rough, but you're mentally prepared. You shutgun a sixteen ounce can of miller light in your kitchen, chase it with a redbull, and chase that with a pull of vodka straight from the bottle. By the time you make it to the front door you're already considering calling a cab just to take you accross the street to your friend's car. You empty a couple of airplane bottles of rum on your way to wherever you're going. You haven't even started your night yet and you're not sure how you got to the car. The whole thing ends somewhere between seven and nine hours later; you only know because it was when the last drunk dial call was made from your cellphone. You wake up wondering where you are, clutching an empty bottle of Jack and your neighbor's dog, even though it turns out you did somehow make it home. You don't have a shirt on, but you are wearing sunglasses. There's three messages from your boss, the last one saying your fired for atrocious things he saw on the security camera, and then one from your grandma wondering what the message you left at 5am said. Your head is splitting and your pants are covered with piss. For some reason there's a used condom in your back pocket. Your ass kind of hurts; you hope it was from a fall.