If you have a commercial site, you need SEF URLs, and this is the extension I recommend to everyone.

After looking at the options, I tried OpenSEF first - it had good reviews at the time and was free. I liked it, but ran into problems with certain modules and some extensions. After putting fixes into the code and working around issues, I needed to go with another approach.

SEF Advanced does just what I need it to do, creating nice URLs and is usually supported by a wide variety of extensions. I use it on my sites and on every client site.

Out of all the SEF options, this is the one that I've found to be most widely supported. To me, one of the big advantages of Joomla is all the extensions that are available, and therefore the SEF choice needs to be supported as widely as possible.

Issues? Installation can be tricky - especially the first time. It does require ion cube to be installed (no big deal to me, although I've read how others aren't happy about it). And it is definitely limited to the domain name it's licensed on. That can be a pain when getting a new site going, but in the long run it's not a bid deal.

This is the choice for any commercial site.

Tried Phil-a-form for a client website. It's nice with lots of power. Unfortunately, with that power came complexity, and it was a little out of reach for the client (who doesn't have any programming background).

Then tried RSForm. It's simple to use, which is great. But it also provides some nice hooks to get the form just the way I want it.

nice work. great component.