If you were around for the GBA or DS and following emulators and homebrew on said same the name FluBBa would be very familiar (vintage site archives). Old homebrewers never die it seems and instead trickle out various updates and new emulators. In this case as a lot were variously alpha and quite buggy some might have missed them or had them slip their mind, some still will be this but collectively are very much worth knowing about. This post then serving as a bit of an overview of the goings on there, though some will possibly be familiar from earlier times. In many cases DSi mode homebrew is recommended, unlike the DSi itself, for the power boost as many will have dedicated versions to take advantage of it.
https://github.com/FluBBaOfWard?tab=repositories covering a lot of the various pieces of code, including individual elements of the emulators, though more individual items listed below. Flubba's twitter page for various updates.
NGPDS which does Neo Geo Pocket (Color)
GBA somewhat early version of said same
S8DS, an "8 bit Sega" emulator that covers
https://gbatemp.net/threads/s8ds-new-release.601262/S8DS supported systems list said:SEGA SG-1000 / SG-1000 II
SEGA Mark III
SEGA Master System J, 1 & 2
SEGA Game Gear
WasabiGBA!, early stage GBA port of the WasabiDS Watara Supervision emulator
Original WasabiDS DS version of the emulator
Nitroswan, Wonderswan emulator for the DS
There is also a GBA version
NitroGrafx, PC-Engine/TurboGrafx-16 emulator for NDS
Arcade emulators for various arcade games
Github linkslist of things said:Black Tiger/ Black Dragon. https://gbatemp.net/download/blacktigerds.37036/
Double Dribble. https://gbatemp.net/download/doubledribbleds.37038/
Ghosts'n Goblins. https://gbatemp.net/download/ghostsngoblinsds.37049/
Green Beret / Rush 'n Attack / Mr. Goemon. https://gbatemp.net/download/greenberetds.37040/
Iron Horse. https://gbatemp.net/download/ironhorseds.37041/
Jail Break. https://gbatemp.net/download/jailbreakds.37043/
Punch Out. https://gbatemp.net/download/punchoutds.37059/
Son Son. https://gbatemp.net/download/sonsonds.37044/
Yie Ar Kung-Fu. https://gbatemp.net/download/yieards.37045/
GBA versions of a few of those have also been made available, though note many are rather early stage code
Also worth mentioning at this juncture is wavemotion's StellaDS that builds on AlekMaul's earlier emulator to give rather nice Atari 2600 with DSi enhancements that should make most things playable if you are using DSi mode homebrew. Still seeing updates as well with several earlier this week.
A DSi and DS with memory expansion port of Command and Conquer (Tiberian Dawn and Red Alert.
Covert Operations, Counterstrike and Aftermath expansion support also contained) has also been made available in recent times by mrparrot2 which should serve to supplant the older port made some years ago.
MSXAdvance (originally one of Flubba's emulators) also got a slight update in a fork by patters to autoselect mappers
Patters also managing to get PCE CD support working in pceadvance (was originally a feature but rather limited) in more modern times https://gbatemp.net/threads/pceadvance-cd-rom-support-howto-required.610542/ as well.
Also while it was covered on the front page then ScummVM DSi port was updated a few months back for those that missed it
You are encouraged to visit any of the GBAtemp threads for the relevant projects to comment there but this will be left open for things without threads at this time.