Off the top of my head...
Campione! (Kissing cute girls defeats gods.)
High School DxD (Breasts defeat gods and demons along with a little help from butts.)
Antimagic Academy (Umm... gore and girls?)
Cube × Cursed × Curious (Curses and girls.)
Gakusen Toshi Asterisk (Chunni terminology and girls.)
Psycome (Violence and girls. Also: Love kills.)
Maou na Ore to Fushihime no Yubiwa (Monster girls.)
Ichiban Ushiro no Daimaou (aka, The Title Makes no Sense, but The Story is Good.)
Kenshin no Keishousha (Everyone has a sword fetish, and odd English, like 'Swordies'. >.< )
Zero no Tsukaima (Pretty much the definitive of standard-MC in standard-western-fantasy-world with standard-harm series. Featuring Louise, probably the originator of the short, flat-chested, ultra-violent tsundere type. One of my favourite series' despite the cynical description.)
Seikoku no Ryuu Kishi (Err... Zero no Tsukaima with dragons?)
Seirei Tsukai no Blade Dance (Zero no Tsukaima with less tsundere violence and more harem.)
Shinmai Maou no Keiyakusha (Probably the most Borderline-H novel on here.)
Tokyo Ravens (Probably the most normal one-girl-one-boy romance novel on here, but it does seem like it's getting haremy later on.)
For odd values of romance:
No Game No Life (Brocon/siscon and, err, love-via-curse?)
Onii-chan Dakedo Ai Sae Areba Kankei Nai yo ne~ (Brocon/siscon, and trying-to-be-oblivious MC.)
There's probably double this number if I probably looked through the list and added one-volume-only-stalled translations and others I've forgotten. Honestly harem-romance-with-action (Silver Cross and Draculea, Date a Live, SAO, Accel World, etc) is probably half the novels that are being translated.
but it has amazing characters and a really interesting plot)