What mandatory items do YOU carry in your pack?

I was reprimanded this weekend for not having a combat-ready daypack with skins in it.
So, this is actually a two-pronged question: 1.) what backpack do you use (brand/model/size)? and 2.) what must-haves do you pack so you're ready for spontaneous bc action?

Thanks!

What pack and contents depend on factors such as what kind of trip, location and terrain, which depends on weather. 

The one constant that never changes, a flask, at least.

Any 2-3000 cubic inch pack can do the job, but one with a good ski strap system and shovel/probe options is nice.  My wife uses one of the BCA packs with the hydration tube in the shoulder strap.  Pretty slick.  I use a Dana Designs pack that I've modified with a few things.  If you have a pack that size that you like, take it to a gear repair place and see if they can add the features you need.

Bare minimum for "emergency" backcountry readiness is, of course, shovel, probe, beacon and skins.  If I'm taking that stuff, I'll have most of my bc kit ready to go.  Water, food, first aid, repair kit, some extra non-resort layers.

Heh -- on preview, Snoslut has his priorities more in line than I...

In my pack you will find a: shovel, probe, snowsaw, down jacket or wool sweater, xtra goggles, gloves with functional layers, water, 5 almond joys and duct tape, which acts as safety/repair kit.

After a long arduous search, I recently settled on an REI brand Double Diamond pack.  It's about 2000 cu.in. comes with an integrated hydration system with the hose coming out of an insulated shoulder strap, interior pockets for shovel handle and probe, a beaver tail flap on the front for the shovel blade, dedicated ski carrying straps (both A frame and diagonal), reasonably sized top lid and it offers access to the interior from the back panel so you don't have to go in from the top and take everything out of your pack to get to the goods at the bottom.  Jeebus, I sound like an REI salesperson.  But it really is turning out to be a good little pack from me.  Just big enough for a long day trip or it compresses down to work well for resort skiing too.

As for the essentials that I put in it - obviously shovel, probe, skins.  I seem to have glove issues so I bring multiple pairs on every trip.  I always bring a puffy jacket, regardless of the weather.  They're light enough and comressible enough these days that it's worth it to me just in case the shit hits the fan and I need to stop somewhere for an extended period of time.  I'm a 2 liters of water minimum type of person, but I know some folks get by on a lot less.  I second Snosluts endorsement of the Almond Joy...those things rule.  Oh and I'm always sure to have my headlamp.  We've found ourselves out and about much later than anticipated and it sucks to ski in the dark.

Chocolate.

Oh, and a cell phone so I can send text messages bragging about how good the skiing.