Anything by OLIGHT / ITP or 4Sevens is a good bet. Both companies make many different sizes for various applications, from key chain size up to "tactical." Fenix makes some decent stuff too. Streamlight tends to make cheaper lights, but they should still be useful.
What size are you looking for? Something that you plan to carry in your pocket, on a key chain, or big enough to throw a massive beam / defend yourself with (if needed)?
Also, consider what type of batteries you want to use. Do you want something that uses AAAs / AAs, or do you want something bigger like a "normal-sized" Maglite that uses D cells? Then, there are always the 3V CR123A's which most of the high-end flashlights tend to use, due to their superior output (the downside, of course, is that the batteries can be difficult to find).
Just a quick tip: with many of the high-end flashlights, you'll notice a letter and a number somewhere in the description, like Q5 or R2. This is supposed to be a measure of the LED's intensity - the higher the letter / number, the better. So, a Q5 would be brighter than a Q2, but an R1 would be brighter than the Q5.
