Westernmost, Easternmost, Northernmost and Southernmost places of Europe, visited by you

[Mikula]

Visited by me:

Westernmost - Charles de Gaulle Airport, Paris, France, 49° 0′ 35″ N, 2° 32′ 52″ E
Easternmost and Southernmost, too - Ierapetra, Crete, Greece, 35° 0′ 0″ N, 25° 44′ 0″ E
Northernmost - Dresden, Germany , 51° 2′ 0″ N, 13° 44′ 0″ E

[Lucia]

Northernmost - Edinburgh, Scotland (55.95)
Southernmost - Tenerife, Spain (28.3)
Westernmost - Funchal, Portugal (-16.9)
Easternmost - Szeged, Hungary (20.14)

[Jana]

Most northern/western : Dublin, Ireland 53.3498° N, 6.2603° W
Most southern: Amalfi, Italy 40.6340° N, 14.6027° E
Most eastern: Kézdivásárhely, Romania 46.0006° N, 26.1346° E

[MissMischief]

Westernmost - Paris, France.
Easternmost - Athens, Greece.
Northernmost - Stockholm, Sweden.
Southernmost - Granada, Spain.

[Damião de Góis]

Northernmost - Amsterdam, Netherlands
Southernmost - Algarve, Portugal
Westernmost - Lisbon, Portugal
Easternmost - Venice, Italy

[Mikula]

Westernmost - Paris, France.
Easternmost - Prague, Czech Republic.
Northernmost - Stockholm, Sweden.
Southernmost - Granada, Spain.

Stockholm is located more to east than Prague:
Stockholm - 59°19′46″ N,18°4′7″ E
Prague - 50°5′13.92″ N,14°25′15.96″ E

[Ülev]

Westernmost - Plymouth, GB
Easternmost - Lublin, Poland
Northernmost - Lahti, Finland
Southernmost - Crotone, Italia

[Brás Garcia de Mascarenhas]

Westernmost - Cabo da Roca, Sintra, Lisboa (Cabo da Roca is a cape which forms the westernmost extent of mainland Portugal, continental Europe and the Eurasian land mass)



Easternmost - Narva, Estonia (located at the eastern extreme point of Estonia, at the Russian border, on the Narva River);



Northenmost - Stockholm airport, Sweden



Southernmost - Ponta de Sagres, Algarve (southwesternmost tip of Europe)

[alnortedelsur]

Northernmost: London, England
Westernmost: Madrid, Spain
Easternmost: Mallorca, Spain
Southernmost: Ibiza, Spain

But if we go by having been in there, at least by making a flight stop:

Westernmost and Northernmost: Cork, Ireland
Northernmost: Cork and Dublin, in Ireland
Easternmost: Frankfurt, Germany

[Graham]

North: Isle of Lewis, Scotland
West: County Mayo, Ireland
South: Gran Canaria, Spain
East: Cyprus