Cryptopia fell apart. But before it did, it was an easy to use exchange with fairly high volume.
Who is replacing it now?
Bittrex always had good volumes for alts, and their login stats always show you which alt coins had the most change in volume and in price. I use the volume setting to show me the top coins also so that is one very useful way to see which alts are getting popular,,, at least in the terms of trading!