Dave B. tells me that the fixed gear ride we did with the LBS (Family Bikes, Crofton) sold him on the idea of riding fixed. So he's looking at a couple bikes.
I don't have a monopoly on fixie knowledge, not even close. But I got some thoughts.
Dave is considering the Surly Steamroller and the Soma Delancey. Both are nice bikes. The Surly is stout, cheap, and has a grunge sensibility. It's track-ish in geometry, which means fast because you are slung low, but not necessarily a comfortable utility bike though the Geometry is in between track and street. I like the Soma Delancey - it's stylish and looks comfy, and Soma makes topnotch frames.
Of course the big Manufacturer's fixies are nice starting points - though you'd probably wind up customizing bits and pieces here. One nice thing about a fixie is it's stout. The wheel isn't dished, so it tends to stay true really well. There's no shifting, so if you keep the chain properly tensioned, the chain / cog / ring combo last a long time. Unless your name is Trevor in which case you are riding atop a ticking time bomb. You don't need mondo brakes on the fixer because you always have the Human Coaster Brake option. So a cheap or old build is fine. I built a 74 Fuji Dynamic as my first fixie and it was wonderful, other than the amazingly major bottom bracket flex. But the old Trek wheels and a recycled Shimano Ultegra crank on a square taper bottom bracket worked just fine. Lotsa options.
If you want a combination of rugged, attractive, stylish, and Surly Crosscheck versatile, you owe it to yourself to check out the On One il Pompino. You can rig it as a cross bike, commuter, trainer, or if you feel wild, something like a 29'er. It's a little heavy, but it does a lot. And daaaaammmnnn, the styling is amazing. Maybe its looks are like liquorice - you either love it, or gag on it. I'm in the love camp.
I think the Van Dessel Country Road Bob is nice, as is the Kogswell. IRO makes some nice gear too, the Jamie Roy and Rob Roy are pretty sweet, and very economical. Of course an old Schwinn or Colnago or Masi has mucho style, 'specially with high flange hubs...
Whatever you do, flipflop hubs are key. The option of going single speed when your legs are blown is nice, and you can also race single speed cross, which is a test in and of itself. As if merely racing cross wasn't enough.
I like the notion of a fixed gear as a performance utility bike. My Crosscheck is built up with Salsa Delgado cross rims, Surly New Hubs, flipflop, 32 hole. I have only had to true the wheel three times, once initially, once after a brutal cross race, and once after breaking a spoke on a 200 mile ride down the C&O with about 50 pounds of luggage in a pannier, and the spoke only broke because I crashed out trying to hop a 6" diameter downed tree. (Yeah, with panniers. I didn't claim to be smart). I run it with 700x35 treaded touring tires. Even on club rides. Which makes my legs really hurt, but that which doesn't kill us, makes us... subject to ridicule from the Dedicated Followers of Roadie Fashion we ride with. But screw them. The utility bike notion works for me, and I'm happy with the bike as it is, kind of plain but all about function and fun. I do major fixed gear mileage, for racing training and because I just like the damn thing.
Did I mention we were doing some light off-roading tonight after work on our fixie cross bikes? Yeah, try that on your Pista with 700x19 tubulars... You can get a lot of fun from a "utility" rigged fixie.
Dave talks a little about pimping his new ride up a bit, but unless it's an old classic, or a modern bike converted with an eccentric hub or weld-on track forks, I'd feel guilty about putting Phil hubs on a beater cross/trainer bike. Now if I was going to really pimp it out, black or colored Deep Vee rims with DT 240 or 340 hubs, aero spokes, Chris King headset and the green and copper Brooks saddle. But pimping a Surly is kind of creepy, like hotrodding a VW.
In the end, Dave - or anybody else going fixed - you need to find a bike that moves you and develop a vision of your own. My vision is basically a Jeep Wrangler of a bike - simple, pared down, nice (but not bling-ey) components, and highly, highly functional in a lot of different arenas. Some guys like bikes that are like Ferraris, others like old MG's, and still others like Cadillacs. It's a very personal thing and in the end, the bond between fixie rider and bike is a lot closer than the bond between the normal geared bike and the rider. Ultimately, when buying fixed, you have to follow your heart, not the advice that I (or some other equally presumptious idiots) give you. Try a couple, or at least read up on a few different ones, and you'll find one that wins your heart.
Just make sure it doesn't capture your mind, too, because until you get really used to riding fixed, there's a danger you'll forget to pedal, an offense for which the bike will punish you promptly. I guess that cantankerous side is part of the charm, too.