If you don't mind a larger mod, the Wismec RX2/3 is awesome. It can use either two or three 18650 batteries so you can choose whether you want the most battery capacity or something slightly less bulky. It can output 200 watts with three batteries, or 150 watts with two batteries.
If you want something more compact but still able to handle fairly high wattages, I like the Wismec Presa series. The Presa TC100W uses one 26650 or 18650 battery and can output 100 watts, while the Presa TC75W uses one 18650 battery and can output 75 watts.
All of these mods are inexpensive but well-built, and all can also use
ClockSelect's myevic custom firmware which offers a lot more features and customizability than just about any mod available (regardless of price), while still remaining as easy to use as the stock firmware if you aren't quite ready to delve into things like power curves.
The RX2/3 and Presa TC100 can also fit 24 mm and 25 mm tanks and RDA's without any overhang. A lot of great, newer atomizers are larger than the "old standard" 22 mm diameter. With the smaller Presa TC75, 24 mm atomizers fit with only a tiny bit of overhang (0.5 mm on each side).