Phaneuf, Biggs and Bozak
For 1st, Mantha, Sproul and Weiss.
Biggs was a target of Detroit in his draft year, a throw in prospect that they could maybe see some untapped potential with a change in scenery. Bozak was one of their targets when he was a UFA for a brief period before settling for Weiss. He'd also be a solid top 9 depth option for them. Phaneuf, well we know they like him. Detroit can pawn off Kindl and/or Smith for depth to shed cap space.
Leafs get good future assets obviously. Mantha has a lot of potential and adds a size dimension that we lack a bit on the Marlies, but definitely has lost value in the last year. Sproul is a solid RHD offensive defender prospect, could be NHL ready if/when the Leafs purge a lot of their roster players. Weiss is the big cap dump, and I don't think he'd be thrilled with being coached by Babcock again, but perhaps with a lot less depth in front of him he could rejuvenate his career just a bit.