.. just to the left of the no'3 is a brick chimney stack, just to the left of that is a pinkish chimney stack, on the face of the pinkish chimney stack is something that looks like a clock saying around 7:10.
Fair point.
Another possibilty for the 50th clue then is the chimney stack above the "Valco" sign, it now has two pots on it but in the original picture (and on Google Street View) there is only one.
These are my final answers for anyone who's interested:
1.Big Brother
2.Sherlock
3.Wizards vs Aliens
4.Downton Abbey
5.Blockbusters
6.2012 Olympics
7.Wallace & Gromit Prom
8.Eurovision Song Contest
9.The Voice
10.Dallas
11.The Bridge
12.Trollied
13.Fresh Meat
14.Euro 2012
15.Britain's Got Talent
16.Merlin
17.Birdsong
18.Hustle
19.Titanic
20.Doctor Who
21.Family Guy
22.Wimbledon
23.Twenty Twelve
24.The Thick Of It
25.Wartime Farm
26.Strictly Come Dancing
27.Queen's Jubilee
28.Hunted
29.Good Cop
30.Line of Duty
31.The Paradise
32.True Love
33.Plane Crash
34.Whitechapel
35.Volcano Live
36.Brazil with Michael Palin
37.Pointless
38.Vikings
39.Great British Bake Off
40.The Choir: Sing While You Work
41.Bletchley Circle
42.2012 Paralympics
43.Lewis
44.X Factor
45.Helen's Polar Challenge for Sport Relief
46.Mad Men
47.The Hour
48.Coast
49.DCI Banks
50.Red Dwarf