LeBron has dominated in nearly all of the playoff games he's ever played, but these moments stand out I'd say:
48, 9, 7 on the road at DET in game 5 of '07 EC final to win in 2 OT, later pushing the Cavs into the NBA finals:
http://sports.yahoo.com/nba/boxscore...gid=2007053108
Buzzer beater victory over Orlando in game 2 of '09 EC Finals (and 35, 4, 5, although Cavs went on to lose this series):
http://sports.yahoo.com/nba/boxscore...gid=2009052205
40, 18, 9 in game 4 on the road in Indiana last year (down 2-1 in the series), essentially putting the team on his back in a virtual elimination game:
http://sports.yahoo.com/nba/boxscore...gid=2012052011
45, 15, and 5 on 19 of 26 shooting on the road in Boston for game 6 of '12 EC finals (an elimination game, was perhaps as focused as I've ever seen him, reminded me of MJ that night):
http://sports.yahoo.com/nba/boxscore...gid=2012060702
Beating Durant and the toughest home environment in the NBA in game 2 of the '12 NBA finals with a 32, 8, and 5 line (which paved the way for the Heat victory in the series):
http://sports.yahoo.com/nba/boxscore...gid=2012061425
There's obviously a lot of other playoff games where he lead his teams to road victories with huge performances, but these seemed to be the most significant/memorable.