SQL Efficient way to locate an example of each combination - sql

Question

Is there a more efficient way of querying a table (or collection of table) for all possible combinations of a few columns, I'm currently running group by and then max, but this doesn't seem to be the most efficient way.
SQL Fiddle for the below example: http://sqlfiddle.com/#!2/25f8b/3
Example Table
ID | Name | Age | City | Color
--------------------------------
1 | Dave | 10 | London | Red
2 | Dave | 11 | London | Purple
3 | Dave | 10 | Paris | Orange
4 | Jim | 10 | London | Red
5 | Jim | 10 | London | Green
6 | Jim | 11 | London | Lazer
etc... (around 500,000 rows)
Currently doing:
SELECT max(ID), Name, Age, City, Color
from People
group by Name, Age, City
To produce:
MAX(ID) NAME AGE CITY COLOR
1 Dave 10 London Red
3 Dave 10 Paris Orange
2 Dave 11 London Purple
5 Jim 10 London Red
6 Jim 11 London Lazer
Note 4 is missing as it's a exact duplicate of 5
3 Is included as it has a different city to 1, even with same age/name
However currently on this massive database it takes around a ten minutes to return the results (note it's actually a join of a few tables)
Is there a more efficient way to return the same results? I was imagining a mass collection of SELECT * WHERE name = %, age = % and city = % LIMIT 1 or something similar

Answer 1

To get the different combinations there is as reserved word DISTINCT :
SELECT DISTINCT Name, Age, City
FROM People
This gives the same result as :
SELECT Name, Age, City
FROM People
GROUP BY Name, Age, City
However it is limited :
If you add a column (like Color), it is included in the combinations analysis
You can't use aggregate functions, like MAX
I don't know if it's any better performance wise