Careful with this question - it'll bring on a slug fest of chain lube opinions. As suggested before, search the forum for this.
For a lubricant, 3in1 is a perfectly fine lubricant; however, it is a magnet for dirt. Dirt and grit on your drive train can accelerate wear on your drive train and leaves you with a wet, messy dirty chain.
Depending on what and how you ride, a "dry" lube is state of the art for chains these days. Some are wax based, some are petroleum based. However, dry lubes need to reapplied often, especially when they get wet. I mountain bike, and I apply the lube after every other ride, or sometimes after each ride. I don't know what this interval would be for a road bike, but I assume it depends on riding conditions. The advantage to dry is when I "clean" my chain, I use a dry brush to knock of the dust and reapply the lube - probably takes a few minutes total. A wet chain (like with 3in1 oil) would need a soaking or wet cleaning process - a real hassle. And if you have a dry chain and accidentally touch it with your leg, you won't get an instant chain tattoo.
I've tried a few different lubes (Tri Flow, Pedros Ice Wax, Krytech (sp?)) but for the past 4 years, I've been using Prolink. It goes on wet, but evaporates to dry. Prolink is also great for lubing the cables and pivots, so I cut down on my inventory of lubricants. My ride buds use White Lightning, Park Chain Lube, and Rock 'n' Roll. Ask x riders and you'll often get x+1 opinions.
I do have a can of 3in1 on the shelf for general purpose lubrication on non-bicycle items. As I said before, it's a great lubricant, but maybe not for a bicycle chain.