"I love you too."
Translation:Eu também amo você.
Você is the familiar form. It is used more commonly in Brazilian Portuguese. Although "Eu te amo também" would be perfectly normal Brazilian Portuguese. The second person singular formal forms are "o senhor" (masculine) and "a senhora" (feminine). Although these are second person in the sense that they mean "you", because it is formed as if it were a third person, you must use that conjugation of the verb.
Take a look near the end of this page: http://www.dummies.com/how-to/content/introducing-yourself-in-portuguese.html
It's also right, but while "Eu amo você também" can be used in many instances, "Eu amo também você" is likely to be used in more specific contexts. For example, you have two kids and then you tell the boy "Eu te amo". Then, your daughter looks at you. She is upset, and then you say "Eu amo também você".