Regarding the new Ubuntu Software Center that came with 11.10: I hate it. I think the old one is much more functional and is prettier than the new one. Is there any way to get the old Software Center back?
Yes, it is but it takes a bit of doing.
Download the previous version, Un-install the latest version using synaptic package manager it is called "software-center" It will want you to uninstall a ubuntu-desktop or xubuntu-desktop, let it uninstall this package then re-install it after it is done un-installing the software center.
next close synaptic package manager and open the download of the old software center with GDebi Package Installer, If you don't have it install it first. The old version will install only if the newer version is uninstalled first.
after installing the old version open synaptic package manager locate software-center, highlight it and on the file bar click -Package -Lock Version, this will prevent it from being updated all the time.
As an alternative, you could try Synaptic. It is also a package manager, but with a lot more functionalities.