M5 Carbon Highracer, which in recumbent circles is referred to as an M5 CHR. This model held a world 1-hr record for recumbents, until it was surpassed by another M5 model. Not wit me as the rider, though!
Optima Baron lowracer - Possibly the most popular lowracer built. Most people would rate a Baron as extremely fast, but it's only my 3rd-fastest recumbent out of 4. It's not a great climber, but it's a great choice for hilly rides due to its predictable low-speed handling and dual disc stoppers for insane downhills with hairpins I have it set up with a bit wider tires, to handle rough roads around my home.
NoCom - This is often labeled as the fastest production bike in the world. I can attest, it's scary-fast. I've done moderately hilly metric centuries at 21+ mph. when everyone else was patting themselves on the back for averaging 16. It came to me as a broken frameset, which I had to repair; but at least the price was right. I also had to custom-make a hub for the front wheel: 80mm dropout spacing and disc brake. With a 6-inch seat height, I use my helmet as a kick-stand.
RANS V-Rex24 - My first recumbent, and it's an oldie but goodie. V-Rexii are classics in their own right, but V-Rex24s are rare. This one has been through many forms, from 3x7 to 3x3x7 (63 speeds) to the current 3x9, as well as being my fairing experimentation platform. At various times it has sported small front fairings, larger ones, full nosecones, tailboxes, and even a full head-out coroplast body. Now it's my choice for leisurely rides.