Soulcalibur (I mean, gotta have it, it's not even been ported anywhere in full since and it was and is brilliant)
Resident Evil Code: Veronica & X (it's a classic - translate the latter but give the option to play the original as well)
Aero Dancing/Wings trilogy (amazing and unique flight simulators - do them with translations of 2/F's
Taikenban expandalone, the third game
i and its own expandalone
Jikai Saku Made Matemasen)
Crazy Taxi & 2 (good to have both for the different cities and play style, blazing fast 60fps with great dense visuals showing the system could handle open world games if anyone made them)
ECCO the Dolphin: Defender of the Future (ambitious and unique adventure worth honoring)
Marvel vs. Capcom 2 (you know the drill)
Test Drive/F355 Challenge (brilliant sim/homage/love letter/passion project)
Virtua Striker 2 (fun arcade football/soccer shenanigans with a beautiful port proving Dreamcast could handle Model 3 games despite Sega Rally 2's issues #1)
Zero Gunner 2 (awesome rotating helicopter shmup)
Test Drive Le Mans/24 Hours (second only to F355 in that vein)
Virtua Tennis 2/2K2 (no reason for the original imo)
Power Stone & 2 (both are worth having for the different content)
Rayman 2: The Great Escape (probably the definitive version at the time and a really good game at that)
Elemental Gimmick Gear (unique JRPG)
Grandia II (best version at the time - if not still given the remaster's issues - and a really fun game, even if the story was a bit cliche)
Tech Romancer (neat 3D anime mech/giant robot fighting game by Capcom, sad it's 30fps)
Psyvariar II (fairly good looking shmup)
D2 (I'd say it's the precursor to amazing survival horror titles like Code: Veronica, bizarre and unique and a huge upgrade in gameplay to previous Warp efforts)
Shenmue & II (token must-have people would whine about I guess, I could do without them given the saga's future)
Daytona USA/2001 (great remake with beautiful polished visuals, screw the haters)
Metropolis Street Racer (amazing looking racer most of the time with unprecedented polygonal details in the tracks, it just takes a while to get to the better/longer stuff)
Dead or Alive 2 Limited (Japanese upgraded version, translate it fully or simply default to the English/subtitle settings)
Project Justice (so underrated vs Soulcalibur, DOA2 or the 2D Capcom fighting games, it's up there)
Ikaruga (duh)
Skies of Arcadia (this was the opposite to Grandia for me, great story and everything else but the combat, at least the standard party combat, was more dull)
Sega Rally 2 (maybe fix the fps but iconic either way)
Tokyo Xtreme Racer 2/Highway Challenge 2 (no reason for the original in this one case, it's just the same but way better imo, though it's also a huge shame it didn't bring back the drifting of Saturn's Shutokou Battle '97, it would have been a classic with that)
Mobile Suit Gundam: Federation vs. Zeon DX (the first of the long-running initially Capcom-made series - translate it, maybe give the option to play the non DX version as in the game's two disc release, Idk why it was a thing but maybe there are legit reasons to want both)
Cyber Troopers Virtual-On Oratorio Tangram (so good to look at and play, beautiful port proving Dreamcast could handle Model 3 games despite Sega Rally 2's issues #2)
Jet Set/Grind Radio (duh)
Space Channel 5 (still a unique experience as far as rhythm games go, maybe translate
Part 2 as well)
Maken X (I guess this can be omitted as a filler game, it's not amazing but it's a pretty neat first person action game with SMT-esque visuals and story)
Bangai-O (rad 2D arcade shooter)
Record of Lodoss War (the true console Diablo, more than PSO)
Border Down (best side scrolling shmup maybe, to differentiate from all the top down stuff)
Zombie Revenge (underrated arcade brawler)
MDK2 (great classic third person shooter, this was the best version at the time with the PS2's lacking in visuals and performance, it was nerfed in difficulty - like all future ports - too)
Under Defeat (not my favorite shmup to play, ZG2 is way better, but it just looks great)
Hydro Thunder (add some variety to the racing games, I borderline want
4 Wheel Thunder also but, beautiful and polished as it is, it's kind of plain and boring, especially compared to how frantic Hydro feels)
Sakura Taisen/Wars III &
IV could be finally translated for some visual novel + SRPG mech battling goodness but maybe only if they do a Saturn mini with
Sakura Taisen/Wars & II (they're also on DC but barely enhanced, I think they fit Saturn better), especially as IV is a homage/send off.
Bonus games (only because of lack of online, if they actually added that then they could be main games, maybe some lesser games above like 4 Wheel Thunder could fit here instead too)
Phantasy Star Online Ver. 2 (you know this one but hey if they added a freaking ending that would be nice)
Propeller Arena (excellent and super polished arcade combat flight deathmatch shenanigans)
Outtrigger (better suited to console play than Quake 3 imo)
The Typing of the Dead (with any standard keyboards supported)
Hidden games (with controls/options that can support both retro - if this thing can connect to CRT - and modern lightguns like Sinden/AE/Gun4IR, unless of course they bundle a gun, then they could be main games, otherwise just don't bother)
Confidential Mission
Virtua Cop 2
The House of the Dead 2
Maybe add some Atomiswave and Naomi games if possible, it's a crime some of these didn't get ported back then (but others weren't great anyway).
Guilty Gear X (because Dreamcast itself didn't get the 1.5 version, otherwise I guess the existing release could be in the main list)
Guilty Gear XX Accent Core
Dolphin Blue (one of said crimes)
Neo Geo Battle Coliseum and
Samurai Shodown VI could be added as fairly uncommon SNK games but I guess they aren't their best anyway.
Maze of Kings,
Ninja Assault and
Lupin the 3rd: The Shooting could be alongside the earlier hidden lightgun games, maybe
Lupin the 3rd: The Typing alongside TTOTD.
Maybe
Virtua Fighter 3tb has to be there somewhere too but not for me (I don't find the port itself bad, the game itself looked outdated and crude by 2000 standards even if it was jawdropping in 1996 and it was super barebones and plain) and if so I'd add
Fighting Vipers 2 with it.
Maybe
Capcom vs. SNK 2 - Millionaire Fighting 2001, but it seems to me this series didn't turn out so great, I dunno, let FGC folks decide.
Maybe more Capcom fighting games like
SFA3,
SFIII variants,
Vampire Chronicle,
JoJo's Bizarre Adventure, etc., maybe more from SNK as well,
Garou, but yeah, you can get most in other ways (including some games I main listed but they're iconic for Dreamcast, gotta have 'em).
Maybe the
Sonic games but I never feel like playing those so I didn't include them, that's just me, I guess they'd have to include both Adventure games though, much like Shenmue.
Maybe some more shmups but just the best, don't flood the library. There are other potential filler games like
Red Dog,
Fur Fighters,
Toy Commander,
Super Magnetic Neo,
Starlancer,
Silver,
Soul Reaver,
Time Stalkers, or even a translated
Napple Tale.
Sega Bass Fishing (port proving Dreamcast could handle Model 3 games despite Sega Rally 2's issues #3), Sega Marine Fishing and especially Sega Bass Fishing 2 are also cool games but they wouldn't do the fishing rod, even less likely than the lightgun, so no thanks.
And that's about it. Plenty GREAT games even we have to exclude some licenced stuff (but not all, can't have no F355/Daytona) and/or third party stuff (but not all, can't have no MvC2/Project Justice) and/or Japan-only stuff (but please do). No dodgy stuff just because they were rare or unreleased.
Almost everything has been ported.
WRONG, plus many of the ports were on now, even if not then, equally dead systems, while others were trash like Soulcalibur not having all content or Zero Gunner 2 being the somewhat dodgy - version by City Connection. How's a third Genesis mini on top of constant rom releases less ported?!
Edit: had Zero Gunner 2 listed twice, replaced one with Psyvariar II.