That's what I've been doing, I started watching BB1 in February and haven't stopped since, I'm nearly at the end of BB5.
I'd hoped to start BB6 but I think the new series will start too soon so I may not.
The best series in my opinion are : 3, 5, 6, 7 and 9.
1 and 2 are quite nice and nostalgic, so I enjoyed watching them. 4 is tame, has some good moments but on the dull side.
8 is fairly good but overshadowed by 7 and 9 either side of it.
10 is okay...11 I do not like.
And the Channel 5 ones I haven't found online, but if so then 14 is the best, followed by 13, followed by 12.