Maybe you didn't understand the question, he didn't ask you what your opinion on mechanicals vs fixed, sounds like he's already made the decision on that. He asked what the favorite mechanicals are from the guys who already use them. Stay focused and on topic.
Rage makes great heads. I've used many different kinds from them and have had great results from all of their heads. I'm currently using the hypodermics and they are awesome. Huge holes, fly great and very durable. I've never had their head fail and I've shot a moose, turkeys, Whitetail, muledeer, pronghorn and 7 elk with them. Just make sure you use a heavy enough arrow with them to ensure you have enough energy to open the blades on impact and get the penetration you need for them to work the way they should
The good thing about a forum, Shaun, is that longbow can respond however he wants. The OP said are there any brands to avoid - if you can interpret longbow's answer he simply meant "all of them". But you love stirring that pot for no reason.
As for Hypodermics - I had one fail on my best deer and since then have avoided them. I have had success before though, and seen lots of success with them though.
The rage xtreme chisel tip (2.3") have left bigger wounds than I have seen out of any other broadhead. Blood absolutely everywhere. I have heard good things about Trypan and may test them this year. You lose almost half inch in cutting diameter, but they are very strong and durable and have a back cut on the blades.
Kind of a newer brand, but you can also look into SEVR. I have seen great success stories with those, including Sean Morgan the giant slayer.
I sit happily in the fixed broadhead group mostly, but I think putting yourself into either box isn't healthy. Most important thing is to find one that flies good for you!