I'm all for Digital Sega! Based on the recent re-released classics like Guardian Heroes, After Burner Climax, REZ HD, Daytona USA, Sonic CD, Virtua Fighter 5: FS, Space Channel 5 :P2, House of the Dead 4 and even Monster World 4 translated etc not to mention Jet Set Radio and NiGHTS on the way. Digital Sega is best Sega.
I'm totally down for more of this, Segas classic games are the reason we are all Sega fans, if they are all brought back as lovingly as these have been I'm so down for it. Even more so if it means theres a possibility of a sequal!
As Aki said, I would also love to see perfect console ports of Arcade games we never got. I'm looking at Ollie King, Wild Riders, 2Spicy, Virtua Cop 3, Shining Force Cross Raid and of course Border Break! (many more too)
Then there is the new releases, I /loved/ Renegade Ops, I want more! I'm also very excited about The Cave as Monkey Island has always been one of my favourite non-Sega series. I would like Sega to get behind some of the best indie games plus release some new AAA games for digital, like PSO2.
Classic Game highlights I would love to see brought back for digital release:
Shenmue 1&2 (of course)
Skies of Arcadia
Panzer Dragoon, PD:Zwei, PD:Saga, PD Orta
O.TO.GI 1 & 2 - (loved these games so much.)
Shining Force 3 Part 1,2,3
Dragon Force 1,2
Valkyria Chronicles 3 (common Sega!)
Also, I've always drempt of an online version of Dragon Force where everyone plays togeather across a huge world creating kingdoms and battling each other for land. They kind of did this on the N-Gage with 'Pocket Kingdom' (anyone remember that?) but I want that idea brought back and revamped. Would be so awesome.