For about eight months now i have been with Wanadoo. This is a 512k connection with a 2GB limit (they want £20 to upgrade to 1Mb)
I have not found this limit to be restrictive...... 'yet'. I'm not sure if they are applying their limits yet ,but i have downloaded more that 2GB before now, within the allowed month and not found any problems.
At £17.99 a month i am happy with my ISP.... SO FAR!