It's tough to narrow down the peak of Klopp's Liverpool to any one season, but in terms of a best calendar year, it's a much easier decision; 2019 stands alone.
Yes, the long wait to lift the Premier League would go on just a few months longer, but by New Year's Eve, that outcome was hardly in doubt; after winning 18 of their first 19 games, drawing the other, Liverpool led the league by a margin of 13 points with a game in hand.
An unreal performance in the Premier League
But let's talk about Liverpool's Premier League performances of 2019. Yes, there was some disappointment in May after narrowly missing out on the title to Manchester City, but the performances were generally strong.
After losing the first Premier League match of the year on January 3rd, the Reds wouldn't lose in league play again until after the calendar had turned to 2020.
They also drew Leicester at home on January 30th; they wouldn't drop points at Anfield again for the rest of '19.
In fact, the end of the 2018-19 season and the start of '19-20 combined to form an 18-match winning streak in Premier League play.
All in all, Liverpool played 37 Premier League matches in 2019 after losing to City- they didn't lose a single one, and earned 101 of 111 available points.
Of course, 2019 will always be best-remembered for Champions League exploits, and rightfully so. The knockout stages included a memorable road win at Bayern after a tense Anfield draw, a two-legged thrashing of Porto, and the comeback against Barcelona that could not require less of an introduction of explanation.
Naturally, the highlight of the campaign was lifting the trophy after a season-ending win over Tottenham in Madrid.
In terms of domestic cups, the 2019 FA Cup was lost on January 7, shortly after the league loss to City, while the Reds had already been knocked out of the Carabao Cup in early 2018.
There were several memorable moments
As far as the first half of the 2019-20 season, October featured the iconic 5-5 match against Arsenal in the Carabao Cup, eventually resulting in a shootout win, although the club were eventually eliminated after playing a youth squad while the first-choice side competed in the Club World Cup.
Speaking of the Club World Cup, Liverpool lifted that trophy for the first time in December 2019, after winning goals from Bobby Firmino in tense matches against Monterrey and Flamengo.
Earlier, Liverpool had won the other mini-tournament into which they were entered as UCL champions, the UEFA Super Cup, in which they took down Europa League champs Chelsea in a penalty shootout.
This year was also one that saw plenty of Reds rack up individual accolades. Virgil van Dijk was at the top of the list in this regard; he won the domestic PFA and continental UEFA Player of the Year awards, and became just about the closest runner-up in the history of the Ballon D'Or.
Speaking of football's most prestigious individual honor, a staggering seven Reds were finalists for the award; six of those finished in the top 20 of voting, and the duo of Sadio Mané and Mohamed Salah joined Virgil in the top five.
That pacey winger duo would share yet another honor in 2019; they joined Pierre-Emerick Aubameyang as joint winners of the Premier League Golden Boot.
Mané also just edged out Salah to be named the African Footballer of the Year, perhaps a case of voter fatigue as the Egyptian King had won the previous two editions of the award.
Does any other year compare?
So what else could be considered the greatest year? The only answer is 1984, as all three trophies of the Club's iconic "treble" were lifted- a First Division title, a European Cup, and a League Cup, rather than the FA.
This spring also included the end of a remarkable goalscoring season from the club's all-time leading goalscorer Ian Rush, who slotted in 47 goals in all competitions in '83-84.
This included a tally of 32 in league play, topping all scorers across England's top flight, paralleling Salah and Mané's 2019 exploits.
But how did the club fare domestically in that calendar year? In the 1984 half of the 83-84 First Division season, they drew 9 times and lost 3, and started the next year in horrid fashion; first 11 games included 4 losses and 5 draws.
As far as the peripheral trophies that come with winning plenty of championships in the previous campaign, the FA Charity Shield was a loss to Everton of all teams, Argentine champs Independiente used a sixth-minute goal to pull off an Intercontinental Cup upset, and Juventus took the European Super Cup in a 2-0 victory.
So which year is the club's greatest ever? In terms of the overall joy delivered to fans, it's hard to argue against the trio of 1984 trophy lifts, including both league and European titles. that being said, in terms of the "best" football being played, and the quantity of strong performances put out by the Reds, 2019 has to be the best we've ever seen, and by quite some distance at that.