1. Summer Dream - Tohoshinki
2. Summer Time - NEWS
3. Natsu Love Romance - Morning Musume
1 and 2 for sure, although not necessarily in that order. 3 is hard to define for sure but there are a few more that could go there.
Also for 3:
Natsu Remember You - Berryz Koubou
Yuke Yuke Monkey Dance - Berryz Koubou
Yume Miru 15 - S/mileage
Seishun Song - Yajima Maimi (C-ute)
I guess that's all I can think of for now. I'm listening to DBSK/Tohoshinki's Mirotic album now, and nothing is clicking too much. Though I'd listen to them, anytime, any season, so I guess it doesn't matter. Oh! What about Take Your Hands? That's an epic energy song.
Or the Hahaha song.