MERCS – I've been working on building a dedicated MERCS table. Currently I'm feverishly working on building a massive amount of ISO shipping containers. My goal is to have at least ten of these built and painted for games of MERCS.
What I like about these is the versatility they provide in setting up a table. They stack easily and can add a level of elevation that is consistent and simple. With MERCS using cards to measure it becomes tricky to use more complicated terrain as you can't get the card inside of buildings or around corners etc.
To go with these I've picked up a Zuzzy mat. These are really great if you don't have space to store a full size table. The mats are nicely detailed and fairly simple to paint.