I can think of a few actually, and I don't watch that much anime! :D Two of my faves are Death Note and Azumanga Daioh, both have no mushy stuff in them. Having not watched many other animes I can't know for sure, but I have a feeling that Naruto, One Piece and Bleach probably don't have much romance either, they certainly aren't in the romance genre. I also watched a bit of Lucky estrela and Black Cat, while I haven't finished them (I have to say I kind of gave up on Black Cat a little) I couldn't see any romance and they also weren't in the genre.
Fullmetal Alchemist(the 2003 version) has no romance except the last minutos of the last episode. My friend told me that Hunter X Hunter has no romance in it. However, I am not sure since I have not watched it yet.
Zettai Bouei Leviathan managed to go the entire series without any romance in it. None of the girls even had little crushes on each other. The closest it got was that all three girls loved their family members very much. Is that enough to be considered "love" for this question?
EDIT: Oh, I did think of one scene though. The giant swamp dragon did seem to have a crush on Leviathan. But she was clueless, so no romance was engaged.
Natsume Yuujinchou: My favorito animê and it has no romance. (would have pictured but someone already did). Good plot line, well animated, great music: beautifully done. It made me feel so happy with every connection the main character makes as you take the journey with him to find true friendship and acceptance. Highly encourage everyone to check it out!
Blue Exorcist: Action and supernatural. This one was fun to watch and I liked all the characters.
Sands of Destruction: This one is an adventure. Been a while since I've seen it but remember it was fun to watch.
07 Ghost: No romance- is all about action, fantasy, and sobrenatural powers. Good plot but can be a bit slow between the action. But when the action comes, it is good. I really enjoyed the series only bad thing is, is that I don't think there will be a season 2 (which it needs to finish the story). .................................................. (what is pictured) K-project: This is a really cool animê with no romance. Just mainly about a mystery and action with a good story line. It is a little hard to follow at the end but it has a good twist.
Well, the list could go on and on, since I'm not really into that gushy-mushy stuff, but I'm too damn lazy, so the first one from the topo, início of my head is... Puella Magi Madoka Magica. Again, I'm lazy to describe it or whatever, but even though it's genre is 'Magic', it's pretty sad and dark. Personally, I very much enjoyed it ;)