I have found that a creamy light yellow with high gloss white for the trim works on the inside.You can mach almost any cabinets and carpet to it so painting ahead of time is no trouble. I think white is so bland and washes the place out.For the exterior I always stick to earth tones.They go well with the landscaping.
Hopper
Alright so we are talking about best colors, what about quality of brand? I see Keith talk about Benjamin Moore, which i absolutely love and used entirely for my home, little high end for rehabs, even though i see he said use it for exterior and cheapy for inside. ;D
Behr from HD, never impressed me. Glidden is cheaper than Behr and i like it better, Most times i like to use the Promar line from Sherwin Williams, decent price and great to work with, and local stores will set you up with contractor pricing and discounts. 
For the inside, I use a house brand from the local paint store “SureTone”…works OK. I use off-white satin (scrubbable) for the walls and white semi-gloss for the trim. I buy in 5-gal buckets. You can usually work a deal with local stores if you use them and ASK!
I have heard excellent reviews of the paint from Lowes…American Tradition but have not used it myself.
Keith
I used American tradition in my own home and it works great. I use satin on the walls and semi on the trim. I hate hi gloss and flat. hi gloss shows all inprofections and flat is hard to clean so i keep in the middle. just my opinion. i used olympic exterior (also from lowes) on a keystone piece over my door and it went on well. very thick paint.
I have used American Traditions from Lowe’s 5 gallon-It is excellent for exterior I used Walmarts Colorplace brand of interior country white worked awesome for price and coverage. I have used KILZ brand for primer and did’nt like it but used American Traditions primer and is thicker and covers better-price is good too. Also have used Enterprise off white from Lowes for interior and was good for the price.
Lowes has just recently started opening stores locally, so i havent had a chance to use their paint yet. I have used Kilz and Bin for stain killing only and worked well for me.