After about twenty minutes on solving  Einstein's I really got into it, and then I was done in about ten minutes. After you figure out some important steps, it is not even that hard.- 

Here is the solution (please highlight):  The German owns the fish.

House	1	2	3	4	5
Nationality	Norwegian	Dane	Brit	German	Swede
Color	Yellow	Blue	Red	Green	White
Cigar	Dunhill	Blends	Pall Mall	Prince	Bluemasters
Animal	Cats	Horse	Bird	FISH	Dogs
Drink	Water	Tea	Milk	Coffee	Beer

 

If you feel like you are stuck, here are some of the first steps:

First of all here are all the clues:

 

1. The Brit lives in the Red house.
2. The Swede keeps dogs as pets.
3. The Dane drinks tea.
4. The Green house is on the left of the White house.
5. The owner of the Green house drinks coffee.
6. The person who smokes Pall Mall rears birds.
7. The owner of the Yellow house smokes Dunhill.
8. The man living in the centre house drinks milk.
9. The Norwegian lives in the first house.
10. The man who smokes Blends lives next to the one who keeps cats.
11. The man who keeps horses lives next to the man who smokes Dunhill.
12. The man who smokes Blue Master drinks beer.
13. The German smokes Prince.
14. The Norwegian lives next to the Blue house.
15. The man who smokes Blends has a neighbour who drinks water.

 Lets start with setting up a table:

 

House	1	2	3	4	5
Nationality
Color
Cigar
Animal
Drink

 

The first most important clues are that the Norwegian lives in the first house, the Norwegian lives next to the Blue house, and The man living in the centre house drinks milk. From this we can fill out three blanks in our table:

 

House	1	2	3	4	5
Nationality	Norwegian
Color		Blue
Cigar
Animal
Drink			Milk