Excel Favourites Add-In
As you work in Excel, the files that you've used most recently appear at the bottom of the File menu. The default number of files that appear is 4, and you can increase this to 9, in the Tools>Options dialog box, on the General tab.
If you'd like more than 9 entries, and some control of the list order and names, you can download and install Ken Puls' XLG Favourites Add-in. Stephen mentioned this add-in yesterday in the comments, and I've installed it to try it out.
The add-in creates an XLG item in your File menu, where you can open and manage a list of favourite files.
You can quickly add the current workbook to the list, and use the Manage XLG Favourites command to rename the items, and change the order of the list.
I've got several files that I uses every day, and this should make it easy to find and open them quickly.