Sherwin Williams, or Glidden, or what have you, just not the big box store. Ask the professionals to help you find some colors that you would like. Another suggestion would be to find a feng shui professional in your area to give you some ideas. You would need to pay for these services...
Once you pick a color, have the store mix a quart of each (body and trim) and then go home and paint part of the house (like the front of the garage to one side of the door) in a 6 sf patch. Live with that for a few days and then decide what you like.
In my experience, stick to lighter colors than darker ones. The lighter colors reflect the sun's heat, and don't bleach out as quickly as darker ones.
The colors you pick are also going to be affected by the type of house you have (colonial, mission, craftsman, spanish, etc) so take a picture of the house along with you to the store.
Do buy the best exterior paints the store offers, Sherwin Williams makes a good one, and DO plan to powerwash and prime the house before you paint. IF you decide to spray (I don't recommend it unless you are going into the house painting business) make sure you use plenty of tarps to keep the paint off your roof. Be careful walking on your roof with tarps on it. (Talk about an adrenalyn rush!)
Painting is all about prep work and quality materials. The big expense is the labor, and you don't want to do it more than once. Use good materials.