Most of people thinks that MEM -3 is quite interesting. After their terrific latest game (104-93 for the Spurs @ MEM), they absolutely have to win if the want to play the final (not possible ... sorry guys).
I don't think it's possible for several reasons:
1/ This year, San Antonio is so focused on their game, they don't come to lose. SAS' goal: victory!
2/During the playoffs, SAS showed so much concentration during each one of their games: 4-0 against LAL,4-2 against GSW, 3-0 against MEM (for the moment )!
3/Latest matchups: during 2013: 5 games: 4W for the Spurs and 1 W for Memphis (spread +2)
4/Strength and Weakness:
Check this link and go in the "Strength & Weakness" table, you'll find all details: http://parlayz.com/statistics/bask/nba/match/36222
Memphis offensive and defensive efficiencies aren't good at all and on the other hand, Spurs are quite relevant in those fields.
Most of all, just because I think the Spurs want to end this final as soon as possible, they'll do whatever they can to win this game!