Can someone help me identify these plants.

And their function?
Some have overgrown part of the garden and before I go Terminator on their A**es I want to know more.

The spikey one looks like Equisetum arvense (horsetail)

First one is indeed horsetail.  Some people use the young plants medicinally.  If you have goats, they are toxic to goats, being a thiamine inhibitor and causing "goat polio".  
Horsetails spread by underground runners, and are a job and a half to get rid of.  In my experience, they like moist, shady banks and clayey soil.

What can be done with horsetail besides cutting them? Toxic to goats, does that also include deer? repellent? Can they benefit chicken or ducks?
I read they're super ancient, they might have lived so long because they're useful, any info?

I'm using them in the tea blend I've been giving my mother to help speed healing in her broken thigh. For the same reasons that it's supposed to help the bone heal fast and strong, it's also supposed to be very good for the teeth.

The plant itself is coarse enough that one of the traditional uses of it is a scouring brush for cleaning pots and pans.

One thing to watch out for is that it is one of those plants with a strong reputation for sequestering pollutants. That may mean that it's a good option for helping to clear pollutants from land. It also means that if you're not confident that it's growing in clean land and water, you are taking a risk if you ingest it.

Horsetail can be used to ward against blight and mildew on your squash plants. Find out how here.

@ Laurent:  I don't know if it is harmful to deer or not (close relative to goats).  Domestic goats don't always know not to get into it, but wild deer might have more smarts.  It can be fatal to goats, and though I don't want deer eating my garden, I don't want to kill them, either.