eUKhost - http://www.eukhost.com
I've had a VPS with EUKHOST for 3 years now. The experience for the most part has varied from bad to utterly terrible.
Although the customer service agents were always available and friendly, they generally aren't able for their job.
Some unprofessional things that they do are:
1- Repeatedly ask for your Administrator password in cleartext - text which will be emailed to you after your support chat has finished.
2- Log into your VPS and make changes using the Administrator account and make no audit trail of their changes. Ofter (in my case at least) leaving the VPS in a half-broken state.
The most recent problem (December 2010) was that they gave 8 days notice to tell me that my VPS will be decomissioned. 8 days not a problem if there wasn't much going on on the VPS and you are ready and waiting to do a migration, but some people actually use their VPSs! In my case I have 18 domains and websites running off it. To get the DNS updated for all the sites will require contacting a number of different people. 8 days is woefully insufficient time to allow for a full migration. Had I been on holidays it would have been a nightmare situation.
Worse, after only 6 days (with 2 days remaining before the date I was told the VPS would be turned off) I wake to hear a voice message telling me the the VPS had already been turned off.
So, they killed it 2 days early and only informed me of this after they had done it. Not really the height of professionalism.
I was also double charged each month for a year until I noticed it and emailed in. They were quick to admit to the mistake, but it would be nicer if the customer did not have to watch out for these things.
I have only used their VPS service. Their shared web hosting and dedicated service may be fine. But I would steer clear of the eUKhost VPS service at all costs.