I had been using a highlighter for a while, but one day my best friend handed me one of these and I have only used it since! Obviously not the same tube...
I know it's on the expensive end of makeup products, but it really is worth it. The pen is so easy to use, and just a few dabs under your eye gives you enough product to smooth out and highlight. I do recommend getting one that is suited for your skin tone, as it can make all the difference in how your final makeup look turns out.
I originally bought this for my wedding make up, as I was doing it myself. I had heard sooo much positive feedback on it and was told not to waste money on anything else. And.... they were right. It's perfect. Great amount of coverage without looking heavy or 'drawn on'. It reflects the light wonderfully and really hides those unwanted dark circles under the eyes. It's my absolute go-to concealer BUT it doesnt come cheap. I do limit it to nights out or special occasions but it's well worth buying.
Tips: Hint to friends and family about how much you love this - they might just surprise you on your birthday! :-)