WSPBuilder
Personally I use WSPBuilder for packaging and find it much easier to work with than VSeWSS. However if VSeWSS is working for you then that's great.
One of many the benefits I found of using WSPBuilder is that it's easy to integrate into a build system. It's just a simple, but clever, commandline tool.
Batch File
For deploying multiple SharePoint solutions to our customers I usually provide a batch file that contains the necessary STSADM command and prompts them to enter any environment specific data i.e. site collection urls etc...
SharePoint Solution Installer
There is also a nice GUI installer,called SharePoint Solution Installer, that you can use in-conjunction with SharePoint solution files. Check it out it might suit your needs.
alt text http://i3.codeplex.com/Project/Download/FileDownload.aspx?ProjectName=sharepointinstaller&DownloadId=18625
SAF - SharePoint Action Framework
It's worth pointing out SAF; which is an extremely comprehensive framework that can automate installation and configuration tasks, using either MSBuild, Powershell, Stsadm or a custom SharePoint feature.