Recently bought a whole lot of gels to try, at the race pack collection for Standard Chartered Marathon. I wasn't the one running, but Bernice who took part in the 10km run helped me buy different brands and flavours of gels to try. Got the gels at a good price too, think it was mostly $10 for 4 gels.
Strong flavours, might be shocking to those trying gels for the first time. Quite watery, which is better than those gooey kind which makes your throat sticky. Not sure where to get.
Milder and more pleasant flavours, good for those who likes Lemon Lime or Cola flavoured gels. Also watery. Think can get from a few shops at Velocity/Novena Square
Sticky gel, only Chocolate has an acceptable taste. First gel I tried was the Tri-berry flavour, was quite horrible. Chocolate is fine because it tastes like the chocolate cream in the Yan Yan snack. Can be found at GNC stores.
Science In Sport:
Best gel in terms of taste so far. Its watery and refreshing, with good tasting flavours. However it comes in larger packs, so it will take up more space. Can buy at many stores around Singapore, check out http://www.2xsfbsports.com/ The nearest store to my place is at Bikes and Bites, at the old Bukit Timah fire station. $3.50 each.
Have not tried Hammer Gels or other brands, let me know how they taste like! Most important thing to note when trying gels is the taste. Best is to stick to the brand/flavour you like and use only that when you need, instead of trying new flavours all the time while out riding.