I favor the following:
Lara Bar for breakfast (one of the few pre-made energy bars with no added sugar or sweetners...primarily dates and almonds). The Apple, Cherry, Coconut/Chocolut Chew, and Cinamon Bun are my favorite flavors with Ginger, Lemon, and Key Lime Pie coming in second.
Pemmikan also makes a fairly unprocessed energy bar that is very low in sugar. Get the Carob/Coconut as it's the tastiest (REI should carry these).
I pack a mixture of almonds, cashews, and walnuts (or pecans or pistachios) along. I roast and season them myself, but you can buy them pre-roasted for cheap at Trader Joes or other stores.
I also pack along dried fruit, preferably banana, mango, apricots, and figs. Again, I score these at Trader Joes and i opt for the UNSULFURED, uncolored, unsweetened ones.
For lunch I usually nosh on the nuts and dried fruit and more often than not I also have a slice of home-made pizza along (whole wheat flax infused crust topped with a variety of veggies).
i also usually have some super dark (73% or higher) chocolate along for desert. the only drawback to chocolate is that is can dehydrate you (but then i'm usually carrying 3L of water on a ski day, so i cover that base).
The combo of the nuts and dried fruit should provide ample amounts of energy and sugar without overstimulating your body with all kinds of additives.
i also have some recipes for power lunches i copped out of a men's health magazine a few years ago. i can't recall all 4 of the sandwiches, but one was simple Granny Smith apple slices and peanut butter on whole wheat bread. again, the combo of the sugars from the apple and the protein from the peanut butter makes a great energy combo.
i'll dig up the other 3 sandwiches and post 'em here in the next couple of days.
there was also an article on dirtbag ski bums in Powder a few years ago and one of the guys gave his recipe for a "power bar". off the top of my head it mixed peanut butter and M&M's on wheat bread, but there were a few more additives, as well (again, it's that combo of sugars and proteins).
Bklyn, DonDenver, Tsavo, and a few others have eaten lunch with me and enjoyed the simplicity of the meal and the energy effects on the hill (in fact when i meet up to ski with Bklyn her first comment is usually "Did you bring those nuts and the dried fruit?"). The added bonus is that you can carry a small bag of the nuts and fruit and it keeps well (won't get crushed or mushy or anything like that).