Tottenham Hotspur
Harry Kane
This year has been good for Spurs, in terms of their league form. They finished third in 17/18, and in 18/19 (as of Matchday 19) they are in third again. They again finished above their rivals Arsenal in the league, and in the World Cup, many of their top players achieved success in various means. Kane, Dier, Alli, Trippier, and Rose were all part of the England side that reached the semis. And goalkeeper Hugo Lloris was the French winning captain, as France won their second World Cup in history.
Off the field, the new stadium has caused undue headaches, with no firm opening date as yet. However, despite not signing anybody in the transfer window, they haven't been deterred, and are very strong in the league all the same. They also reached the FA Cup semi-finals, but lost to Manchester United, via a goal from ex-Arsenal star no less, Alexis Sanchez.
To choose the best player from their crop is difficult since over the calendar year they possessed many high performers. But in this case, it would be Harry Kane. He cemented himself as a prime global striker with his Golden Boot at the Russia World Cup, and whilst missing out to Mohammed Salah of Liverpool for the Premier League Golden Boot, Kane scored more than 30 PL goals alone in 17/18. In 18/19, as of Matchday 19, is firmly amongst the mix with Arsenal's Pierre-Emerick Aubameyang and Mo Salah.
His off-the-ball movement too has increased, and for both club and country, he often drops deep to create and influence plays. He is far more than just a tap-in merchant, which formed his characterisation in his earlier career.
Honourable mentions
Son Heung-Min
Christian Eriksen
Mousa Sissoko
Mousa Dembele
Toby Alderweireld
Dele Alli