Depends what kind of energy you want, theres slow release carbs, which are good for long runs/endurance work. or fast release, (high sugar content) for that 'sugar rush feeling'
(both being CH2, carbohydrate based)
slow release examples:
(mainly whole grain...or brown as it were)
Fast release being:
jelly sweets/any sweets
fruit (containing fructose rather than glucose which is better for you)..bananas are a good.
you can purchase various CH2 gels in different flavours,
also if you dont want to buy Lucozade etc you can make your own with squash and glucose or fructose powder which you can buy from health food shops, the advantage being you can have any flavour you like. and its cheap like the budgie.
I have some of that, some extra oats, some frozen berries, some mini weetabix and milk into a large bowel (I use a pint of milk easily) and a cup of tea.
After that 2 sausage, 2 potato cakes (from asda) and 2 eggs with some bread.
Keeps me going until 14:00-15:00 (and I eat after training at about 08:20-08:50).
Also, nuts (almonds especially) are full of healthy fats