I have been working with different hosts for about 5 years now. I have used sapphiresoft.co.uk, Dreamhost, Netfirms, godaddy, ipowerweb, register.com, reseller zoom, grab your hosting, and trexhost, just to name a few.
At the moment I am with Scala Hosting and couldn't be happier. I have been with them on the Scala 1 package for about 2 months and they have been great (I also plan to upgrade to a larger plan soon). According to webhostingstuff they have maintained 99.99% uptime, with one outage in March. My siteuptime reports do not show this, so it may have just been the server they host their own site on.
Their prices are great, and they offer a decent amount of space, bandwidth and features. The server that I am on is an 8 core xeon setup and has been exceptionally fast.
The best part of Scala Hosting is definitely their support. Since I have been with them I have not experienced one time that their live chat support wasn't online. Also I had sent a ticket in for assistance with installing an SSL certificate, and they had responded to the message and had it installed literally within 3 minutes.
So if you are looking for reliable reseller hosting take a look at them -
www . scalahosting . com
* They also have a $1 for the first month special going on if you just want to try them out.