I can't tell which Rockman game that is just by looking at it, but it's quite possible that Rockman 9-10 actually run at 240p since they were never FC/NES games to begin with.
I wish. Can't speak for the 360 or PS3 ports, but the Wii versions run at 480i (even when the console is set to 480p). An XRGB-3 running in B1 generally gets the right picture, but of course no scanlines.
Until now. Got my SLG-3000 and put it through its paces. Wii > XRGB-3 B1 > SLG-3000 make Megaman 9/10 really look like they're back in the NES era of CRT TVs. Also looks nice with other 'retro'-styled titles like FF4: The After Years and the modern-retro Konami titles like Castlevania Adventure or Contra (note: the title/cut-scene screens in the Konami games and the FF4:TAY font are higher resolution so they just look darker or pseudo-anti-aliased). Note that some games work better with DIP 4 set vs DIP 5 and vice versa. This is very apparent on 480i titles in particular which contain 240p imagery; one setting renders correctly while the other setting renders as a blurry mess. It all comes down to the game and your linedoubler.
Note that due to how the rendering engines were designed, some of these games look much sharper if you set the Wii to 4:3 instead of 16:9 + scaling your display's screen (this is extremely noticeable in Megaman 10 and Castlevania Adventure). This is regardless of any XRGB-3 or SLG-3000 use.
Tested out the Dreamcast with Marvel vs Capcom and Marvel vs Capcom 2 through a VGA adapter. Worked perfectly. MvsC2 was a nice surprise, the characters are properly scaled for use with scanlines such that their looks benefit from the application of the scanlines (although the HUD, background, etc. are at a higher resolution and end up looking darker). I doubt that would be an 'authentic' arcade experience given this was a NAOMI-based game originally that ran at 640x480, correct me if I'm wrong. Still looks nice though.
Also tested out the SLG-3000 with a PS2. The games on Street Fighter Anniversary Collection look perfect, but just to drive the point home about the DIP settings, the SF2: Hyper Fighting needs one of the DIP settings while SF3: 3rd Strike needs the other DIP setting, otherwise a blurry mess ensues.
A minor inconvenience at worst. Meant to try Mega Man Anniversary Collection but didn't (480i title), I'd expect results similar to Megaman 9 and 10. Mega Man X Collection was fine, but it already outputs at 240p so the XRGB-3 already took care of that before.
As a bonus experiment I also pulled out my copy of FFX and gave it a run (note: this game has a 'unique' resolution of 512x416 before scaling by the PS2, which makes it a bit difficult to work with; if you use any of those HD Xploder-styled solutions to output 480p from a PS2, it comes out in the wrong aspect ratio). Tried in XRGB-3 B1 mode without the SLG-3000; a rather bad solution, too much detail is lost from the image thanks to line-doubling. The SLG-3000 makes it better, but to be blunt, I found less detail was lost hooking the game up directly via S-video to my old Commodore monitors (shadow-mask or scanlined versions) than doing this. XRGB-3 B0 mode at 1024x768 + SLG-3000 scanlines wasn't a bad look; the placement of the 1024x768 version of the SLG-3000's scanlines gave the game a higher resolution look (while of course still rendering at the original resolution, getting scaled by the PS2 and then getting scaled by the XRGB-3), effectively pseudo-anti-aliasing at the expense of a slightly darker image and the scanlines. This is a game that really just needs a good deinterlacer rather than scanlines, but if it floats your boat then that's your call.
Apologies for the lack of imagery to go along with this.