Here are images of known to me miscellaneous metrocards, transfers, single ride, trial cards.

Trial metrocards, both cards are made of paper and probably reflect trial colors for upcoming introduction of metrocards:

Green

Orange

This metrocard has MTA logo on the back side and probably was trial version:

MTA Logo Front

MTA Logo Back

Metrocards issued for NY-NJ PATH:

Quick Card 11-Trip Front

Quick Card 11-Trip Back

Quick Card 20-Trip Front

Quick Card 20-Trip Back

Quick Card 11-Trip Back 2nd version (front the same as for 20-Trip)

Gold color front side PATH metrocards:

718 Phone

212 Phone

511 Phone

Private Queens Express Bus metrocard, that private company became part of MTA already.

Queens Bus Front

Queens Bus Back 1st version

Queens Bus Back 2nd version

Transfers between buses were introduced together with metrocard transfer between subway and buses as well as single ride metorcard for subway (not valid for transfer).

Bus Transfer 1995 front

Bus Transfer 1995 Back

Bus Transfer 1998 – 2002 Front

Bus Transfer 1998 Back

Bus Transfer 1999 Back

Bus Transfer 2000 Back

Bus Transfer 2003 Back

Bus Transfer 2003 – Present Front

Bus Transfer 2003 Back

Bus Transfer 511 Phone Back

Single Ride Metrocard 1999 Front

Single Ride Metrocard 1999 Back

Single Ride Metrocard 2011 Front

Single Ride Metrocard 2011 Back

Before metrocards replaced tokens passengers were issued special paper transfers in event of broken train or bus or something else happened so trains were not running. Here are samples of those tickets:

Paper transfer

Metrocard issued for New York City Council:

New York City Council Member