Wee this topic's always fun ^_^
Personally, I don't think Dominate _____ is a line of evil spells. Casting it is not inherently evil, no more than swinging a sword is. If you cast it on someone and tell them to go do some business in the village well and everyone gets cholera... yah that's evil. If you tell them to not kill you or your friends, that's not really evil. Swing a sword at baby- evil, swing sword at rope to Errol Flynn over armed guards- not evil.
That said, if a DM thinks its evil, you should ask "Why?" If it's a part of his campaign setting, fine... good to know. If a character in a setting thinks its evil, your character should ask "Why?" and try to meet some kind of understanding. With paladins this can be tricky if not impossible, but just chalk that up to the sun circling the earth, the crickets warding off ninjas, and cat familiars almost always being portrayed as being overbearing towards their Wizard "masters" (term used very loosely).
The answer, as it formulates in my mind, basically states that what Dominate _____ is in the sense of right or wrong shouldn't hinge upon Our rights, Our beliefs, and Our cultural preferences so much as upon the rights, beliefs, and cultural preferences in your campaign. I know all the "inalienable" deals and the potential for platonic truths, but when we get down to it, those have about as much leverage in a dnd campaign as the law of the conservation of energy (here, have a fireball).