BEST SIDE SCROLLING SHOOTERS Please?

[cabdog]

Howdy!

I'm hoping for advice on the best side scrolling shooters on the platform. I'm currently playing the newer/freemium sector strike, but looking for better and/or something new as I know there are a ton out there, I just forget which ones.

Can someone please provide a list or some of their face side scrolling shooters?
I'm not talking vertical, ie. CAVE, but the side scrollers.

Thoughts please?

Thanks in advance!!