League of Legends is an excellent example of a free-to-play game where purchases don't seem manipulative. IIRC, they've said that they make most of their money

League of Legends is an excellent example of a free-to-play game where purchases don't seem manipulative. IIRC, they've said that they make most of their money out of the cosmetic aspect ("skins"). The other thing they do is to enable people to pay to get the new game characters ("champions") faster than the free players (who have to "grind" to get them, and carefully consider their purchases).