I've had several versions of an emergency/first-aid kit. It started out small, but now it takes up a little backpack and is a little more organized.

Inside of the backpack are two seperate bags. Specifically, the one on the right is the first aid-bag, and the one on the left is the "emergency" bag. Also inside the backpack is a roll of duck tape and a large knife I had sitting around.

Inside of the first-aid bag is what I currently consider to be the most needed/useful items in my kit, fairly well organized.

Inside of the kit we have the following:

Top:
3 pk of Super Glue
One each of a hot compress and a cold compress
Three tongue depressors, cloth strips, q-tips
3M Transpore and Cloth Adhesive Tape
Kerelix

Bottom:
Hand Sanatizer
Hydrodortisone Cream
Shears
Vaseline/Petrolium Jelly
Triple-Antibiotic
SPF 30 Sunblock
Deet Bug Repelent
Three 4x4 Gauze Pads
Moleskin

Inside of the center detachable bag we have:

Razor Blade and Fingernail Clippers
Two pairs of Nitrile Gloves
Quick Asprin and Acetaminophen tablet packets
Various Bandaids
Alcohol Pads, Sting Relief Pads, and Burn Relief Cream

On the reverse side are two kotex and five tampons

In the "emergency" bag:

Six more pair of Nitrile Gloves
Cough Drops
Three sizes of Ace Bandages
Two Light Sticks
Plastic Bags
Emergency Blanket
Plastic Poncho
A bag containing 3 tea candles, matches, firesteel, can opener, compas, and a magnifying glass
Paracord
Med Carrier

Inside of the med carrier are as follows, with this description taped to the back:

1) Acetaminophen 500mg
Good for "general" pain. Better than Ibuprogen for fever and headaches.
Worse than Ibuprofen for muscle/joint pain.
1-2 caplets every four to six hours. Do not exceed 1000mg.
Do not use for hangovers or before/with alcohol as it stresses the liver.
Do not use with Vicodin/Lortab/Norco.

2) Aspirin 325mg
Moderately good for pain. For cardiac symptoms, chew and swallow.
1-2 caplets every three to four hours. Do not exceed twelve in 24 hours.
Do not give in case of trauma as it thins the blood.
Do not use with ulcers.

3) Benadryl 25mg
Good for seasonal allergies and acute allergic reactions.
Also good as a sleeping pill.
1 caplet every four to six hours. Do not exceed six doses in 24 hours.

4) Pepto-Bismol
Good for nausea, heartburn, the runs, and general "upset tummy" symptoms.
Take with carbonated, non-caffeinated drink for maximum effect.
2 caplets every half-hour to hour as needed. Do not exceed 8 doses in 24 hours.
Will turn poop a dark color.

5) Excedrin 250/250/65mg
Acetaminophen/Aspirin/Caffeine
Caffeine increases the efficiency of the medications.
Best for migraines, "general" pain, and headaches.
2 caplets every 6 hours. Do not exceed 8 caplets in 24 hours.

6) Ibuprofen 200mg
Good for musculoskeletal pain. Good for fever. Ok for headaches.
3-4 caplets every four to six hours.
May cause upset stomachs, take with food if possible.
Do not use with ulcers.

7) Naproxen RX 500mg
Good for musculoskeletal pain. Good for fever. Ok for headaches.
Longer half-life than Ibuprofen.
1 caplet twice daily as needed for pain.
May cause upset stomachs, take with food if possible.
Do not use with ulcers.

The things missing, that I soon wish to add:

Sam Splint
Triangluar Bandage
A good pair of tweezers
A good whistle
A better pair of shears
Some sort of light source, be it a headlamp or a flashlight, along with extra batteries
An improvised sewing and fishing kit
SAS Survival Handbook
W ater purification tablets
CPR face mask
Signaling mirror