I'm not going to get into the whole "Breast is Best" argument here. I know plenty of moms who love their kids just as much as any breast-feeding mom, yet choose to use formula because that is what worked for them and their families.
So what are the best and healthiest choices when it comes to formula? For starters, choose organic formulas over non-organic whenever possible. Also, go for powdered formula over liquid. It creates less waste, it's cheaper, and powdered formula cans are generally safer in terms of chemical contaminants than the plastic containers used to hold liquid formula. If you do choose liquid, look for formula packaged in a can or in a "safer" plastic container (#'s 1, 2, 4, or 5.) Oh, and just to make things even more confusing ... while I did say that cans are generally safer than plastic when it comes to packaging, make sure that the can is not lined with plastic or BPA resin.
Got all that? Don't worry, I can make it even simpler...
Baby's Only Organic Formula
Enfamil Powdered Packets
Similac Powdered Packets
Similac Liquid RTF in a plastic quart-sized container
When it comes to baby bottles, choose glass, metal or BPA-free plastic.