If you are talking about a somewhat realistic scenario, this is what I'd really love:
1. Rondo re-signs with Boston in 2015 free agency
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Rondo decides Boston is his home and chooses to stick around and be the captain of the proud franchise
2. Avery Bradley re-signs with Boston for $24M/3
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Avery Bradley will not likely ever a star in the league, but he could be the absolute perfect glue guy on a contender.
Bradley is an elite defender who can guard the PG or SG spots and can dominate games with his defense. He's not an elite shooter, but a solid enough shooter to keep the defense honest. He's the type of hard worker and first rate hustle guy who inspires teammates to play harder. He's young with a high upside. A relative bargain at $8M.
3. Boston acquires Carmello Anthony via trade
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BOS acquires Carmello Anthony, Beno Udrih and Kenyon Martin from the NYK in return for Jeff Green, Jared Sullinger, Kris Humphreys and a 2014 1st Round Pick (from the LAC)
Carmello gives Boston the 'Alfa Dog' and elite go-to scorer it has needed required since the Paul Pierce trade.
4. Boson signs Greg Monroe
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Boston leverages enough cap space to sign Greg Monroe in the 2014 free agency.
Monroe gives Boston an excellent #2 scoring option with a legit low post game and a nice touch from midrange. Monroe carries the offese while Melo sits and is a perfect complement for Melo when both are on the court.
5. Boston Drafts Joel Embiid in the 2014 NBA Draft
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Teams surprise everybody by drafting Wiggins, Parker and Exum with the top three picks in the 2014 draft. Joel Embiid falls to the Boston Celtics at #4 overall.
Embiid becomes Boston's defenive anchor and offers elite rebounding and rim protection for the first time since losing KG in the Brooklyn trade. Embiid can produce on offense at times as well.
Final lineup:
PG - Rajon Rondo
SG - Avery Bradley
SF - Carmello Anthony
PF - Greg Monroe
C - Joel Embiid
I'm sure there are better 'pure talent' lineups out there, but this to me is one of those lineups where everybody just fits.
1. Avery, Carmello, Monroe give Boston enough shooting threats to space the floor so that Rondo can get in the driving lanes.
2. Carmello and Monroe can draw frequent double teams, leaving AB with space to hit a lot of open threes
3. Carmello gives an elite go to guy and clutch scorer when the game is on the line
4. Rondo and Bradley forge what becomes one of the NBA's elite defensive frontcourts
5. Embiid's elite shotblocking helps to cover for Carmello's defensive limitations.