Having worked through the top ISPs of the time over a number of years I eventually plumped with AAISP; the 18 months I've been with them have been great.
AAISP (Andrews & Arnold ISP), is a small company based in the South East, providing services general tailored for small to medium businesses, but the packages are priced such that they are also available to the home user.Pros:
- Excellent support over email, phone or IRC. They are straight up and honest about any problems and get to the bottom of issue without resorting to the typical step of blaming the customer.
- Excellent, clear information on faults and customer affecting work via a blog. They are very happy to discuss changes and their impact on their IRC channel.
- Good connection speed on the whole. I get 8096/448 sync on ADSL and can comfortably fill that with downloads with out any problems.
- Great selection of options. All ADSL users get a free domain and hosting. Email supports IMAP and POP with SSL if required. IPv6 can be provided native over the connection (requires a compatible router) or via a tunnel, and you can have a /128 (or /64, can't remember which) IPv6 range. You can have additional IPv4 ranges for free.
- No shaping. You get a clean line
- Support hours are around office hours and now Saturdays, although it's not difficult to get hold of them during these hours.
- Is a little pricey for day time usage but out of hours (1800-0900, all weekend) is unlimited so it's good if you're out at work during the day. I have seen some information that indicates they may have a 100GB cap during off peak, with truly unlimited between 0200-0600.
- Very occasional outages although they don't last long and A&A are good at keeping the customers informed of progress.
If you live in an BT ADSL2+ area, AAISP are currently migrating users across to that for the same prices as their 8Mb ADSL offering.
All in all, I recommend them for anyone who has a good level of knowledge and wants to extra features to play around with (or even do work with).