Hi Sarah,
The dark purplish plants are Aeonium, most likely Aeonium arboreum.* There are many different species of this plant that come in different colors. These are tropical plants and won't tolerate freezing temps.
http://www.smgrowers.com/products/pl...sp?plant_id=45
http://images.google.com/images?um=1...=Search+Images
In the lower front is Stachys byzantian aka lammbs ear.* They get tal flower spikes and will often take over an area quickly if they are happy.* I tend to cut off the flower heads so they don't seed around.
http://oregonstate.edu/dept/ldplants/stachys-b.htm
The spikey plant on the extreme right is an Agave.* I'm not sure just which one, but these plants also don't tolerate hard freezes.
http://en.wikipedia.org/wiki/Agave
The fluffy tall plant could possibly be a Euphorbia of some sort, but I can't see it clearly.* I also can't tell what the red flowered one is.
I hope that helps,
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.