Choosing a web hosting may be a big issue when you start an online business or a new website. When you choose a good web hosting service, you should list your main needs first. Say you want to install a small web site for personal issues, you don't need a huge hosting plan for that, you just need a free domain and a small hosting space like 100 Mega Bytes.
If you want to install a big website, you will need bigger hosting space and you may be in need of more than one domain. So, multiple hosting plan will be good choice for that business. I can suggest HostGate.org to compare the hosting planes there.