I use both, depending on what I feel like at the moment.  I can only use pencils as eyeliner, not the "true" (liquid) liner stuff.  I don't have a steady enough hand for that.  I do think eyeliner (pencil or liquid) defines the eyes more, and since I sometimes wear glasses, I think they bring out my otherwise "invisible" eyes.

The eye pencils I use now (Sephora Hello Kitty Charmmy Kohl eye pencils) are soft enough in texture that they could double as eyeshadow.  I use shadow over it to help it stay put.

I've always used eyeshadow.  When I was younger, I would wear eyeliner with the eyeshadow, but now I just wear the shadow.  I'm thinking about using mineral eyeshadow now.

I happen to love both. I have brown eyes and they seem boring to me so I like to spice it up with colored liner.

I am a huge fan of using shadow as a liner! It creates a nice softer line. You can also wet your brush to make it more dramatic...even a sexy cat eye!! Play with colors as well as neutrals and have fun!!!

i am both.. they are right.. it really depends on one's mood .. but i sometimes do an eyeshadow on my lids.. and a colored eyeliner at the bottom.. i love trying different colored eyeshadows and looks everyday.. when i dont have time to put on my daily makeup routine.. i go to colored eyeliners.. takes less time and can pump up your look in an instant.. but why dont you try both.. its kind of interesting if you mix them all up together.. but dont go over board.. i know its halloween but come on.. hehe

i rarely ever wear balck eyeliner, If i wear it, i wear it in silver and only on the bottom lashes. Lately I started using a dark eyeshadow as an eyeliner on top, and when you have the wright angled brush, i have no need for eyeliner at all! :)

I've been using eyeshadow AS A dry LINER lately!  I love it... It goes on much closer to your eyelashes and it seems to look a little more natural (not heavy).  I just use an eyeliner brush to apply.  I've started to forgoe the whole "eyeshadow on the lid" thing now, but I add a dot of creamy white or vanilla to the inside of my eyes (near the bridge of my nose) and up toward my brows a bit to just "highlight."  Lastly, I add a coat or two of black mascara.  It's simple and quick for a finished eye look.   

I'm a both person, although I do like the look of liner alone. I usually put liner on top of my shadow and then use an eyeliner brush to press more shadow (the same colour as the liner) over the liner for a smudgy look.

Have you ever seen this product before? It's a liner from www.ebeauty.ca that turns any eyeshadow into liquid liner which looks really cool! I think I'm going to order it!

http://www.ebeauty.ca/Vasanti/Eyeliners/Vasanti-Magic-Liner/pages/productdetails?nav=R:940505

I wear both, but it depends on the look. I am playing around with colored eyeliner right now. It is so pretty and really makes your eyes pop. I have green eyes so I am trying a purple gel liner...

If you use a good primer on your lids, like Too Faced or Urban Decay, your eyeshadow will stay put.  I think using eyeliner on lids pulls the tender eye lid skin too much, which will result in sagging.  Benefit also makes "Lemonaide" which reduces redness on lids and acts as a good primer.  I use eyeliner to line my under lids and add powder shadow over it with an angled brush.