With it being a custom sort I'd prob create another table which stores the users preferences, so they'd have a screen with the list of reports and they could tick ones as favourites, make the sort order by that, or given them a preference score and sort by that.
It's a little extra work but how else would you know.
Unless you audit which reports they open and sort by most often. Increase a counter each time? Add a row to a table, that could get big slow though.

I like the list box set up Richard just put out the video.  Check it out it is good and simple to follow .  
I find most of the time not wishing to give the customer to many options as they forget 90% and just use a few 10%.  Find what few they like and they will be happy..  or you will spend a lot of time coding stuff that may never get used
Most of the time I use a dropdown with the selectcase.  SQL is the best way.  set up a form dropdown will sort the form.  then set up a report with that recodrsource, BOOM- What you see is what you get.  
just my thoughts

V/r
Juan

Yeah, I'd go with the listbox and a custom sort order. I kinda prefer that way to the 2nd way I showed in the Extended Cut. I like being in control of my list of reports. You could sort the other method too, but that would involve using a 2nd listbox or an array.

I like what Alex says.. ( Increase a counter each time and sort by the most used )
In the report table you will have 3 fields, Report Name, Report Description, Sort Order  A Number field.
In your table List You will enter the Report Name, Report Description and start out with all of the Sort Orders at 0 or 1
Have the Report List box sort by the Sort Order field.
Then each time the user click on a report in the report list box have it increment the Sort Order number by 1
Then the next time the user opens the Report List box it will have the most used report at the Top of the list.
That way as the user uses it more the most used reports will work there way to the top.
Just another Brainstorm....

Ray: I actually used to do that with my customer list. I had a listbox showing frequently contacted customers on my Main Menu. Each time I opened a customer's form, that counter would increment. Worked well. Forgot why I stopped using it. I should make a video about this. :)

Actually, I was just looking through the TechHelp emails and a few people have asked very similar questions about this recently. That warrants a video! :)

Ya that just seemed like it would be the easiest way for end user as they would not have to do anything,

Here you go, boys: Favorite Customers

Favorite Customers Video is Spot-On,, Good job. that will work Great with a Lot of Reports.
( Increase a counter each time and sort by the most used )