I feel like the standard 80" round is getting dated. While it will always be a classic and can never be replaced, there are many other options available!
Square tables which hold 12 people are great for a smaller function. It creates a more intimate seating arrangement and does not constrict the guests form talking to people only on their left and right as a standard round can do.

A venue filled with smaller square tables is just beautiful. If your reception was to be held in a large, renovated greenhouse with lights strung from the ceiling and your tables decorated with timeless centerpieces, think about how classic your reception would be with intimate square tables, versus large rounds.
Long rectangular tables with bench seating-style. While many may think this is only useful for an outdoor wedding, that is simply not the case. Perfect for a venue which is an odd shape, bench seating creates a more 'family like' atmosphere than the traditional round creates.

There are so many fun style options you can come up with when using this type of table.
Picture centerpieces which alternate in size and shape, going the full length of the table. Your colors can gradually change with each centerpiece. It creates such a pretty image, doesn't it?