first of all, foundation is different from bb cream. Fpundation is thicker while bb cream is much thinner and looks as if you dont have any make up on at all.To answer your 1st question on whether missha's or oslee's bb cream is better, i'll tell you Missha (especially the red one ) is better than oslee's. Oslee is oily and it doesnt last. There are reviews saying that it's not a good bb cream,b esides, if you're looking for bb cream, why not choose Korean brands such as Missha, skinfood, hanskin, dr. jart? Missha's BB cream is good in covering your blemish, pimple marks and make your skin tone more even. I'm using Missha Red myself. It also moisturizes your skin and it's not sticky nor oily. It lasts long. Missh's website for yr reference
http://www.missha.com.hk/v5/main.php
To answer your second question on maybelline, Pure Mineral Healthy Natural Liquid Foundation is quite good. it does make your skin looks luminous. (i've tired this before) and most importantly, it's not expensive. with such a quality and such a price, this product is a bargain. you should try it!!
Moiggi's bb cream is even better than missha and oslee. it's thin and will give you a dewy look. It's easy to apply onto your face. But it's bb cream seems to have been out of stock for a while. i'd say it's the best bb cream among the 3 you've mentioned.