Quality rather than quantity
Must be able to be kept
Include the logo
Only for top clients
Unique, outside the box and something theyll want to keep

Hi
I can offer many ideas for you depending on budget, the type of industry ect. Some ideas:

BBQ sets with logo etched on box or handles.
Aroma reed defusers, with custom scent, logo silk screened on the bottle
Office fountain with logo etched in rocks that are in the fountain
For office, crystal water pitcher and glasses (logo etched on glass pitcher)
Golf balls in custom bag. Bag has logo. Give a special golf ball that is made of "safe" material that can be recycled.
Feel free to email me, and give more specifics, I can develop some more ideas. ConnectTheDotsAdvertising.com