Just off the top of my head;
Spice and Wolf - set in medieval Europe and focuses on trade and economics, top tier waifu included and a great story. You'll want to read the light novels for this one once you finish the anime.
Maoyuu Maou Yuusha - from the same director as Spice and Wolf. Haven't finished it yet myself but it's great so far.
Monogatari - Modern day Japan with a lot of elements of Shinto myths realized, fair bit of ecchi content and a breddy good story. Art style is good, main character is a vampire.
Oreimo - Story follows a Japanese teenager who discovers his younger sister is secretly an otaku. Ecchi, slice of life. Second webm related outlines the plot.
Haganai - Not really any reason to watch this except for third webm related. Story is okay but hardly goes anywhere. Mild feels here and there. Light ecchi, slice of life, comedy