Which Japanese English-Japanese dictionary should I get: Kenkyuusha dictionary or Kodansha's Furigana English-Japanese Dictionary?

Let me elaborate: I am in my first semester of college and I've been taking Japanese for about a month and some weeks. It's fun and I'm pretty good at it. But I know that between semesters students tend to forget certain things that they've previously learned. I don't want that happening to me, so I want to purchase one of these books to keep me going between semesters. But which should I get? My sensei recommends the Kenkyuusha dictionary just because she's used to it and has never seen the Kodanasha dictionary before. I trust my sensei, but I've heard such good reviews from everyone about the Kodanasha dictionary. I have a limited budget, so I don't want to waste money on the book. Advice would be helpful.
P.S. At the moment I am just starting to memorize some kanji and am now starting on japanese grammar, if that matters at all.