Here are the names of the top 50 oldest cryptocurrencies, based on their launch dates:
Bitcoin (BTC) - January 2009
Litecoin (LTC) - October 2011
Namecoin (NMC) - April 2011
SwiftCoin (STC) - October 2011
Terracoin (TRC) - October 2012
Peercoin (PPC) - August 2012
Feathercoin (FTC) - April 2013
Novacoin (NVC) - February 2013
Freicoin (FRC) - December 2012
CHNCoin (CNC) - September 2013
WorldCoin (WDC) - May 2013
Digitalcoin (DGC) - May 2013
GoldCoin (GLD) - May 2013
BBQCoin (BQC) - May 2013
Yacoin (YAC) - May 2013
Mincoin (MNC) - April 2013
Bytecoin (BCN) - July 2012
Primecoin (XPM) - July 2013
Megacoin (MEC) - May 2013
Ixcoin (IXC) - August 2011
Anoncoin (ANC) - June 2013
Devcoin (DVC) - March 2011
Quarkcoin (QRK) - July 2013
Infinitecoin (IFC) - June 2013
Freicoin (FRC) - December 2012
Digitalcoin (DGC) - May 2013
GoldCoin (GLD) - May 2013
BBQCoin (BQC) - May 2013
Yacoin (YAC) - May 2013
Mincoin (MNC) - April 2013
Bytecoin (BCN) - July 2012
Primecoin (XPM) - July 2013
Megacoin (MEC) - May 2013
Ixcoin (IXC) - August 2011
Anoncoin (ANC) - June 2013
Devcoin (DVC) - March 2011
Quarkcoin (QRK) - July 2013
Infinitecoin (IFC) - June 2013
Zetacoin (ZET) - August 2013
Dogecoin (DOGE) - December 2013
DigitalNote (XDN) - May 2014
Nxt (NXT) - November 2013
Reddcoin (RDD) - January 2014
BitShares (BTS) - July 2014
BlackCoin (BLK) - February 2014
Counterparty (XCP) - January 2014
Ripple (XRP) - February 2013
Dash (DASH) - January 2014
NEM (XEM) - March 2015
Monero (XMR) - April 2014
Please note that this list is based on the knowledge available up until September 2021, and there may be newer cryptocurrencies that have emerged since then. It's always a good idea to conduct.