Are there any plug-ins you don't doing an event without? What do you recommend?

Depends what you are prepared to spend. I highly recommend Magic Bullet Looks. Use it a lot.

If your using Final Cut Pro try using Nattress Filter.

Yeah, FCP and AE.

I second Magic Bullet Looks for all your projects! Just makes them look filmic and easy to use, watch out for render times though.

NewBlueFX video essentials. An inexpensive and really quick way to let the colors pop and get rid of that slightly gray cast over the original vid.