I have 5 weeks until I go to the beach and want to be as fit/ripped as humanly possible. If I had to stick to the strictest diet and workout, what would they be?

P90X or Insanity. I have both.  Given the description above I would recommend Insanity.  It has high cardio and should get you ripped in about 30 days.  The P90x requires a lot of upper body stregnth and abs.  Insanity is a better motivator and intermediate program.  You should be able to get it cheap on craigslist or ebay.  Good luck.   Try to maintain a vegetarian diet with lots of water.  Use vitamins and protein drinks for extra energy.  Trust me it's better to follow a course that you play on DVD.  It pushes you harder and motivates you the whole way.

If you only have 5 weeks to become as "fit/ripped as humanly possible," you're not going to get much results. Generally speaking, if you do everything right, you can only gain about 1-2lbs of pure lean muscle and lose a few pounds of pure fat. Everything else will be fluctuations of all kinds of factors. While the advice the others gave are useful, I recommend taking these 5 weeks and kicking off a long-term plan to get into shape. You already admitted you're "not in the best shape of my life." What does that really mean? And why wait until 5 weeks out until doing something about it? It's not the answer you want, but it's the answer you need. Good luck.

Although everyone's body will metabolise at different rates...It should always be a combination of diet and training (80/20). Diet: (depending on body type: approx ratios) Ectomorph - thin and skinny.. 25% protein 55% carbs 20% fats Meso... naturally muscular 30% Protein 40% Carbs 30% Fats Endo... Naturally holds more fat. 35% Protein 55% Carbs 40% fats REMEMBER these are good healthy fats. Not the saturated fats. Excercise: A combination of 12-15reps per set 3-4set of each exercise 3-5 days per week combining 2-3 muscle groups each day with 2days rotation for recovery. Pre workout - Med chain Carbs with protein drink (60-90min prior to training) Post workout - Dual Protein (whey/soy) within 60min (provides fast protein synthesis from the whey and continuous recovery from the soy.) Post workout Endurance (fat burn) Dual protein with Carb (7:1) Aim to burn 500-700 cal below your BMR (basal metabolic rate) to ensure fat burning. Eating slightly extra protein to stimulate muscle growth while burning cals for fat loss. 1.5l - 2.5l of water per day don't forget 1l of water while training. Supplements: Creatine daily 4g-8g /day Glutamine 5g-10g/day BCAAs 8hrs sleep for good recovery. Eat every 3-4hrs Keeping to a healthy diet over the 5weeks will make dramatic changes to your body. Keep off the alcohol - alcohol inhibits fat burning process <80%. A recent client had fantastic result being dedicated to changing his lifestyle

You left out an important piece of  data ...waist measurement.  Its amazing how many supposed 'fit experts' give bad advice.  :( Concentrate on building muscle...strength training.   Forget cardio. In your timeframe it's a waste of time. Google Lean Gains...Martin's a real ego BUT he pretty much invented it. He's techniques work. Also check out 4 Hour Body...again Tim is an ego but his stuff works. The book is nearly 5oo pages but for fat loss and muscle gain ....0nly ~120 pages apply. Get the book and get started ..I'd wager in 5 weeks you might be able to add 10 lbs muscle & lose 10 lbs of fat...IF you even have that much to lose. 6' 2" 180 is either lean or skinny fat.  :(