I have a reseller account with HostGator. I have been with them for many years. I have never had a resource problem with HG. I have always found their support and resources more than adequate for my needs. The owner, Gator Brent is very pro-active in customer service. If you can't get a resolution, I have observed that he will honestly try to help. I had a sticky problem with my ISP a number of years ago. They blamed the problem on HG. I called HG's support line on a Sunday morning. Brent returned my call personally. He had the problem solved in very short order. It did turn out to be the ISP's fault and not HG, but he followed through anyway. I have also heard that he treats his employees well but can't say first hand.
I have my VPS servers at Linode.com. They are awesome! I tried HG's VPS's while they were in beta. I prefer the xen based offerings with Linode or others instead.
A nice feature with both HG and Linode is the ease of expansion. With HG, they will upgrade your account and handle the transfer proficiently. With Linode, it is just button press away. Everything is automated. You can increase all of your server resources to ridiculous easily and quickly.
Jeff