Derek Fisher, CF - the veteran would provide speed and a little power at the top of the order. Always a team guy, you know Fish wouldn't be afraid to take pitches to get on base for the middle of the order. He's also got the leadership skills to take control in the crucial centerfield position.
Luke Walton, 2B - he's the perfect unselfish player for the two-hole. Never afraid to sacrifice himself for the team, Walton will lay down a bunt or move a guy over without having to be told to do so.
Kobe Bryant, SS/RP - who else could bat third? Kobe is the guy you want up there when the game is on the line with a runner on second base. He'd also anchor the defense at shortstop and, since he's the best "closer" in the NBA, of course he would hop on the mound in the ninth if the game was close.
Pau Gasol, LF - the pinnacle of consistency, Gasol would force pitchers to give Bryant something to hit. If they walk Kobe, Gasol has no probem stepping up to be the hero. His disgustingly long arms would also allow him to rob homeruns in left field.
Andrew Bynum, 1B - given that the big man is healthy, Bynum provides a power threat like no other. He is young and undisciplined, so you'd have to expect a lot of slumps and strikeouts, but rest assured that when he gets a hold of one, it'll go. Can't you just see "Boom goes the Bynumite!" on the Jumbotron after he parks a 400-foot homerun?