Travel Tips: Europe Tipping Guide

Tipping breakdown by Country:

Spain:
Restaurant: 1 or 2 Euros per Person(10% at a high end restaurant)
Bars: 0
Taxi: 0
Bell Boy: 1-2 Euros per bag.
Concierge: 5-10 Euros for special request


France:
Restaurant: 15% tip included
Bars: Change
Taxi: Change
Bell Boy: 1 Euro per bag
Concierge: 5-10 Euros for special requests

Italy:
Restaurants: 1-2 Euros/Person
Bars: Small change
Taxi: 0
Bell Boy: 1 Euro per bag
Concierge: 5-10 Euros for special request


UK:
Restaurants: 10-15%
Bars: 0
Taxi: Round up
Bell Boy: 1-2 lbs per bag
Concierge: Special request

Germany:
Restaurants: 5-10%
Bar: 5%
Taxi: 5-10%
Bell Boy: 1 Euro per bag
Concierge: Special Request

Portugal:
Restaurants: Change
Bars: 0
Taxi: Round up
Bell Boy: 1 Euro per Bag
Concierge: special request

Sweden:
Restaurants: Included
Taxi: Round Up
Bell Boy: Not necessary- and if you do 20 SEK -- 
(Thanks to @123ravenet123 for the correction)
Concierge: special request

Switzerland: 
Not customary but rounding up is appreciated

Norway:
Not expected but in general rounding up is appreciated

Denmark:
Not expected but rounding up is appreciated

Belgium:
Service charge included

Finland:
Tipping is optional here and can sometimes be seen as offensive.

Poland:
Restaurants: 10-15 %
Bars: 10-15%


Greece:
Rounding up is acceptable.

Austria: 
Not expected but general rounding up is appreciated.