OK, here goes:
Christ's College - My college and therefore the best, established 1505. College of Darwin and Milton. Has best academic reputation. Ali G went here. Overall objectively 8/10
Churchill College - National memorial to Winston Churchill. Good reputation for sciences. New. 4.5/10
Clare College - Nice college. Good academic rep. On strip of old colleges (Trinity, Kings etc). 6.5/10
Clare Hall - Graduate college. New? Not heard of much 2/10
Corpus Christi College - Small, old but nothing really famous I don't think, but has name everyone seems to know. 5/10
Darwin College - Graduate. Quite invisible. More recognisable name than Clare Hall. 2.5/10
Downing College - Reasonable academic rep - especially for vocational subjects. Good sports college. Mike Atherton went here. Kicking everybodies ass on the river this year - 6.5/10
Emmanuel College - Excellent academic rep. Generally regarded as quite a cool college. 8/10
Fitzwilliam College - Modern but with reputation. Reasonable academically. Sometimes good ents. 6/10
Girton College - Long way away. Traditionally college of female thinkers. Because of history 6.5/10
Gonville and Caius College - Big college quite rich. Steven Hawking is here. Big tradition 8/10
Homerton College - Famous for previously education only college. Quite far out 4.5/10
Hughes Hall - Graduate 2/10
Jesus College - Sporty. Old. Reasonable academic rep 7/10
King's College - Old college. Chapel. Choir. Beautiful. Lefty. Very lefty. Not very good academic rep in recent times. Anti tradition attitude 5/10
Lucy Cavendish - Graduate. Female only. Older than other graduate colleges? 3/10
Magdalene College - Old. Backward looking. Not great academic rep, but lots of tradition. 7/10
New Hall - All female. Has produced female academics 5.5/10
Newnham College - Sort of same as above. Bit older 6/10
Pembroke College - Good academic rep. Old. New master is head of MI6 - 7.5/10
Peterhouse - Old. Public school. Backward looking. Traditional 6/10
Queens' College - Good academic rep. Quite old. On strip (Kings, Catz, Trinity etc) Coolest college 8/10
Robinson College - New. Mostly known for that 5/10
St Catharine's College - Sporty. Not great academically. But on strip of colleges on King's parade. 5.5/10
St Edmund's College - Graduate. New. 2/10
St John's College - Rich, stuck up, old but famous. Good academic rep. Big and lots of history. 8.5/10
Selwyn College - 19th century I think. Decent in all areas. I quite like the buildings. 7/10
Sidney Sussex College - Average college in nearly every sense. Oliver Cromwell went here. Opposite Sainsbury's. 6.5/10
Trinity College - Biggest, richest, most famous. Very good academic rep. College of Newton, Milne, Prince Charles and many more. 9/10
Trinity Hall - Nice. Doing well on river this year. Decent academic rep. 7/10
Wolfson College - Graduate 2.5/10
Hope I haven't angered anyone, these are just things as I see them.