<p>The company I work for is starting to have issues with their current branching model and I was wondering what different kinds of branching strategies the community has been exposed to?</p>

<p>Are there any good ones for different situations?  What does your company use?  What are the advantages and disadvantages of them??</p>

We currently have one branch for ongoing maintenance, one branch for "new initiatives" which just means "stuff that will come out sometime in the future; we're not sure when." We have also occasionally had two maintenance branches going on: one to provide fixes for what is currently in production and one that is still in QA.
The main advantage we've seen is the ability to react to user requests and emergencies more rapidly.  We can do the fix on the branch that is in production and release it without releasing anything extra that may have already been checked in.
The main disadvantage is that we end up doing a lot of merging between branches, which increases the chance that something will get missed or merged incorrectly. So far, that hasn't been a problem, but it is definitely something to keep in mind.
Before we instituted this policy, we generally did all development in the trunk and only branched when we released code. We then did fixes against that branch as needed. It was simpler, but not as flexible.