The first two games are good, but a bit archaic. The second game is a classic. The switch from 1/2 to 3 may be a bit jarring; not only are they completely different gameplay-wise, but 3 has a far more serious tone than the original games. Additionally, 3 doesn't have near as much dark humor as the first two games, and the Brotherhood of Steel organization in 3 has a different characterization and motivation than the previous titles.
