I have a pile of melodeons in the corner and they are:
Old Saltarelle Connemara II in D/G - 2½ rows 12 bass - Use it for almost everything - sounds best! (Jack Robinson, Rambling Sailor, Brown Adam)
Backup new Connemara II in D/G - sadly rubbish in comparison to the old one - use it when the other is being repaired.
New Connemara II in C/F - use it for all the songs Jon can't sing in D or G - sounds nice (Courting too slow, Dawn Chorus, Rambling Robin, lots of Eliza's numbers in Bb, Brown Adam when Jon has a bad throat)
Oakwood Model 7 in D/G - 2 rows 8 bass - Use it for raucous songs & tunes - punchy sound (not a patch on the one that got stolen in 2004 though - that was a beauty), for Prickle Eye Bush, Rochdale Coconut Dance & Sloe Gin amongst others
Hohner Pokerwork tuned to Gmin/Dmin (by myself) - Dry tuned pokerwork in a silly tuning that means that a fingering usually in G major becomes G minor - use it for Copshawholme Fair - Shropshire Miner - Rigs of the Time & Hopkinsons Favourite
Hohner Pokerwork in D/G - use it for fun, morris, sessions, workshops
Dino Baffetti Red Pearl III in E/A - Doesn't get used much - very low pitched - used with Eliza sometimes - good keys though
Bernard Loffet 3 Row 18 bass in D/G/accidentals - New to me - very good system although a bit heavy - I'm using it on some of the new S&B stuff and all of Pete's new numbers for Bellowhead because it's completely chromatic and so's Pete's stuff!
Hohner Lilliput club in Bb/Eb - Miniature club model - lovely old Hohner tone - doesn't get used much, but is on Tunes for the Stoney Steps Hornpipe)
Streb E-melodeon 2½ row - MIDI melodeon - has been used live with Bellowhead abroad in conjunction with my apple laptop to trigger sample banks I have made from recording my melodeons - it works - but I'm currently working with the inventor to help make it "feel" more like a real melodeon and iron out some problems.
I also have a 4 row Jeffries anglo-concertina in C/G, 3 bandoneons, a Bandonika (bandoneon bodywork & reeds but melodeon fingering in C/F) which I'm currently
It's a bit of an embarassment of riches to be fair - I remember dreaming of my first "posh" melodeon when I only had a rubbishy 1 row and the Pokerwork my dad now plays. But one of the joys of being a pro musician is that they're all tax deductable!!!