Liverpool
Liverpool, five times winners of this competition, faced a Group of Death, by means of PSG, Napoli, themselves, and Red Star Belgrade. PSG's renown, with World Cup winner Mbappe and world record signing Neymar, speaks for itself. Napoli, whilst not a small club and a club Maradona excelled at in the past, has been arguably the biggest challenger to Juventus's recent Serie A dominance. Red Star Belgrade, whilst once European Champions themselves, were the weaker side, but the phrase "there are no easy games" didn't become a footballing cliche for nothing.
Liverpool actually lost to Red Star and thus attained qualification via defeating Napoli in the last game at Anfield. They did beat PSG at home, and to finish second to Mbappe/Neymar at all is not disheartening. This was mixed with defeat in Paris to PSG, who ultimately topped the group.
Liverpool is currently, before the 15th Dec weekend, top of the Premier League. And of course, were Champions League runners-up in 17/18. They will be looking to better this, and with their star forward Mo Salah back in form, and with a vastly enhanced defence and midfield vis a vis recent years, they can attain this reality once more. Their last Champions League was in 2005, and bar Gerrard, Alonso, Riise, and Dudek, they man for man have better players than that side.