Here is a list of all Famicom games known to use Expansion Audio : http://wiki.nesdev.com/w/index.php/List_of_games_with_expansion_audio
In this post, I identify the most accessible games for English speakers using each expansion audio chip and describe what needs to be done to play it.
Gimmick! - The original cart alone can go for $200 easily, however, there is at least one other more common Famicom cart (Gremlins 2) with a Sunsoft 5B chip, but obtaining one is something of the luck of the draw. Additionally, one can make a donor NES cart with a Batman Return of the Joker and an AY-3-891x chip, or you can get a INL-ROM NES reproduction board with an AY chip on it.
Lagrange Point - This is the only game that uses the expansion sound capabilities found in this chip, which is exclusive to this game and Tiny Toons 2 Japanese version. Tiny Toons 2 does not have an SRAM chip, battery or any of the passive components to mix the audio, so it would be a large undertaking to get it to work in a NES cart. I am not sure whether the Largange Point board plus a pin converter would fit inside a NES cartridge shell because the game's board is very tall. You may need an external pin converter. Interest in this game has also increased substantially because of a full translation patch.
Just Breed - This is a large strategy RGB from Enix and one of the three games that use the expansion audio of the MMC5. Because of its translation patch, it is by far the most accessible of those games. The original cartridge can have its ROM replaced with a translated ROM burned onto an EPROM, some minor reworking will be required. Because it uses Nintendo's MMC5 board, this can work with a reproduction cart in a NES. The most suitable NES cart is Gemfire, but I suspect that any of the battery backed MMC5 boards will work with some minor reworking. Castlevania III and Laser Invasion will require the addition of an SRAM chip and a battery, not a beginner mod.
Akumajou Densetsu - This is the Japanese version of Castlevania III, and does not have so much Japanese text that it requires a ROM swap to enjoy it. The Famicom board is small enough to fit inside a NES cartridge shell with a converter without difficulty. Madara and Esper Dream 2, the other games that use the chip, do have translation patches.
Rolling Thunder - Most Namcot 109/163 games with expansion sound are not very English friendly. This game is basically the NES Tengen version with better sound. Additionally, Namcot almost always used epoxy-bonded ROMs on their boards because they were cheap. Unfortunately, this makes replacing these ROMs with translated ROMs on EPROMs very, very difficult.
NEC µPD7755C/µPD7756C & Mitsubishi M50805
The NEC ADPCM Speech chip was found in Jaleco's Japanese baseball games, virtually all of which were ported to the NES in the Bases Loaded series. The chip stored and could play back voice samples on command. Grab any one of them, games like Moero!! Pro Yakyuu are as common as they get in Japan, but realize its only a novelty. Of course, the speech samples are in Japanese for the Famicom cartridge and English for Bases Loaded. The NES versions had more PRG-ROM space to store the samples in ROM instead of on a special chip and used the NES's internal PCM channel to play them. The Mitsubishi chip was found in Family Trainer 3: Aerobics Studio, which was similarly ported to the NES as Aerobics Studio. Roll out your Power Pad for that one.
Famicom Disk System
FDS RAM Adapter + FDSStick
Read my review of this product for reasons why you should get one : http://nerdlypleasures.blogspot.com/2015/07/the-fdsstick-compact-solution-to-your.html
See also my list here of games for the Famicom Disk System where I give instructions how to clean the saves, all are easily accessible to English speakers : http://nerdlypleasures.blogspot.com/2015/06/cleaning-saved-information-from-famicom.html
Finally, I have generated a list of all Famicom and Famicom Disk System games that use expansion audio and were ported to the cartridge format :
|Japanese Name||Expansion Sound Type||US Name|
|Gimmick!||Sunsoft 5B||Mr. Gimmick! (Europe/Scandanavia Release, US Proto)|
|Moe Pro! '90: Kandou-hen||D7756||Bases Loaded 3, Ryne Sandberg Plays|
|Moe Pro!: Saikyou-hen||D7756||Bases Loaded 4|
|Moero!! Pro Tennis||D7756||Rad Racket|
|Moero!! Pro Yakyuu||D7756||Bases Loaded|
|Moero!! Pro Yakyuu '88: Kettei Ban||D7756||Bases Loaded 2: The Second Season|
|Bio Miracle Bokutte Upa||Famicom Disk System||None (Japan Cartridge Release Only)|
|Doki Doki Panic||Famicom Disk System||Super Mario Bros. 2 (also Japan)|
|Dracula 2 - Noroi no Fuuin||Famicom Disk System||Castlevania II: Simon’s Quest|
|Egger Land||Famicom Disk System||The Adventures of Lolo (different levels)|
|Exciting Baseball||Famicom Disk System||Double Dribble|
|Famicom Golf - Japan Course||Famicom Disk System||Golf (different courses)|
|Famicom Golf - Japan Course Prize Card||Famicom Disk System||NES Open Tournament Golf|
|Famicom Golf - US Course||Famicom Disk System||Golf (different courses)|
|Famicom Golf - US Course Prize Card||Famicom Disk System||NES Open Tournament Golf|
|Gyruss||Famicom Disk System||Gyruss|
|Hao-kun no Fushigi na Tabi||Famicom Disk System||Mystery Quest|
|Hikari Shinwa: Parutena no Kagami||Famicom Disk System||Kid Icarus|
|Kaettekita Mario Bros.||Famicom Disk System||Mario Bros.|
|Link no Bouken: The Legend of Zelda 2||Famicom Disk System||Zelda II: The Adventure of Link|
|Metroid||Famicom Disk System||Metroid|
|Tobidase Daisakusen||Famicom Disk System||The 3-D Battles of the Worldrunner|
|Vs. Excitebike||Famicom Disk System||Excitebike|
|Zelda no Densetsu (Zelda)||Famicom Disk System||The Legend of Zelda (also Japan)|
|Family Trainer 3: Aerobics Studio||M50805||Dance Aerobics|
|Rolling Thunder||Namco 163||Rolling Thunder (Unlicensed Tengen Release)|
|Akumajou Densetsu||Konami VRC6||Castlevania III: Dracula’s Curse|