the great era of don cab is 93 to 98, though there were some good points about the later albums too. anyway, the first three albums are the ones you need, especially 'what burns never returns', which is an absolute master-piece of instrumental rock.
also, if you like what you hear check out guitarist ian william's side project storm and stress or his new project battles. if you want to hear some stuff in a similar vein (ie - mathcore) try ghosts & vodka or drive like jehu.
Tommy, I think I love you.
Not just the fact that you mentioned the right albums but also Drive Like Jehu (even though I've never heard of Ghosts & Vodka and will have to check them out now).
I can only add: If you are into the mathy part of Don Cab, June of 44 would also be a great option, and if you like the harder edge, Rodan.
In case you're more of a fan of the instrumental-rock-with-drummer-going-insane part of Don Cab, go and give Ruins and The Flying Luttenbachers (their later albums, think The Void or Systems Emerge From Complete Disorder). But those are a lot harder to listen to and have bigger avantgarde influence.
