Mascara is of the utmost importance. If we're honest, we can do without so many parts of the daily makeup regimen. Mascara gives the most bang for its buck in terms of giving visible results in response to the effort put forth. If lashes didn't enhance beauty, the fake lash industry and the lash enhancers ($$$) wouldn't be such booming industries. Now that I've validated my stance as a super lash fan, I'll give my recommendations on some fabulous products that I currently own and use.
I should start by saying that I have decent lashes at baseline. They're light, so without mascara they're almost invisible. But they're decently thick and long. This means I want a mascara that will coat (and color) my current lashes, enhance them by adding thickness and length, and NOT clump them up. That's hard to find. And often the brush has just as much to do with it as the mascara formulation.
For length, coating, and separation: Bare Escentuals Flawless Definition Mascara (above). I use it every day. It does a great job of coating and separating my lashes and adding nice umph without giving spider eyes.
Bare Escentuals Buxom Lash is the one for you. One day that I had used it, my sister kept asking me if I had fake lashes on. I had gone light on the eyeliner that day, so the lashes were doing all the work on their own. It's fabulous stuff and probably better for people not starting out with much at baseline in terms of lash volume. It coats lightly and can be coated to add more volume. This is one of those brushes that I kept and cleaned after I was finished with the tube to use for lash separation and placement in the future. Anyone do that? Keep a mascara brush that worked really well, clean it, and use it post-application for last placement? It's a great idea.
I don't know if you've heard of the more recent "tube technology", but modern mascaras are actually made of a polymer that binds around and extends past your own lashes to add "oomph". There are some even at the drugstore formulated to do this. I've tried one by Loreal (Double Extend Beauty Tubes) to no avail. It was a big disappointment. However, I was pleasantly surprised by the infamous Fiberwig Mascara from Imju. It's been a best-seller on Sephora for a while, and it's all the rage in Japan. I didn't so much care for the product by itself. It comes out of the tube and seems to create little spider webs extending from each lash, but it doesn't do much in terms of adding volume and separating. SO I like to finish my mascara application by using this product AFTER the Flawless Definition mascara (the previously-mentioned product). It adds legitimate length and overall volume.
My last recommendation is actually a cheaper one: Cover Girl's Last Blast Mascara in Waterproof. Drew Barrymore didn't lie. I really do like the product to add just a little something for night's going out or a party scene where I want something special to make my eyes pop. It's waterproof, so I use it as a last coat in the mascara phase and NEVER ALONE. I say this because if you look at the brush, the bristles are almost invisible, which means they do nothing for separating or placing your lashes. It's like rubbing flat paper with black stuff over them. If you have small or sparse lashes, this would be probably be your BEST option. Those bristles will aim wide and slather your little guys easy as pie.
Again, I don't use this one every day, just when I'm going for high-drama lashes to support what is usually already an "eye show" on my face (with dramatic shadows and shading).
I hope these help. Let me know what's worked best for YOU...