I like Heinie's myself. But Novak's and the Yost Retro sight is nice, too.
We've got a picture of properly installed Novak's up earlier in the thread. Here's a picture of what properly installed Heinie's look like. And I included a snapshot of a sight picture with one. No, that's not a night sight on the front.
This is what a properly installed Yost Retro sight looks like. XavierBreath, I hope you don't mind, but I stole this pic off your site from the built you did.
The Yost Retro is a drop in piece, with little fitting needed. Most every other sight needs to have some machining done to fit it properly. Not to pick on you JoeHatley . . . but the installation of those sights, while cheaper, aren't the best example of good craftmanship. I'm frankly surprised Wilson would let something out of their shop like that.
Most of the aftermarket sights require that the rear of the slide have some machine work done. Mill work is done to remove metal to allow the sights to sit flush within the slide, so you don't get those sharp shoulders I highlighted below.
For the majority of folks, this kind of installation won't bother them. But if you decide to carry a piece like this, those sharp edges will wear and tear at your clothing. The other problem you get is the rear sight is sitting higher than designed. Its meant to be machined to sit deeper into the slide. If the sight is adjustable, you might have enough travel in elevation to lower it to correct the problem. If not, you'll need to replace the front sight with a higher front sight post.
The best solution is to have the slide milled and installed properly. It might cost more up front, because that usually demands a refinishing, too. But it looks better, it won't leave sharp edges to cut your clothes and hands, and it makes sure the gun shoots point-of-aim, point-of-impact. If you're unwilling to spend the money to have that done properly, just install a Yost Retro sight.