You know, despite its many years of existence, it still is VERY hard to beat Sierra Designs venerable Clip Flashlight. How many years has it been around? I dunnomust be 15 or 20 by now. It has been updated, or course, with better, lighter materials. But for a solo camper it remains a roomy (it fits two), light (3 pounds 6 ounces), and tough (I have weathered winds of 50 miles per hour in one) tent. And all for a mere $199. A bargainthough right now it's not featured on the Sierra Designs website. Hopefully that's an oversight...and if not, you can find one on the interweb pretty easily.
And, well, compare it to the other options: Keltys Crestone 1 is a very creditable single-person tent, for $119. But its tiny. And weighs four pounds! A little happier is Marmots Eos 1P ($225), which comes in at about three pounds and offers a nice, roomy bit of space. I might also go for MSRs Hubba ($250), a three-pound solo dealy-thing that offers good space and the ease of a free-standing set-up, something the Clip does not offer. But I still would buy the Clip Flashlight. Seriously.
I confess, my own solo" tent is Black Diamonds Lighthouse. Its a single-wall tent that is light (three pounds 12 ounces), roomy (it fits two), and free-standing. Yeah, its $425. Advantage Clip Flashlight!