JPLOP.COM

+10 Toki wo Koe Sora wo Koe
+9 Senobi
+8 Towa no Uta
+7 I Miss You
+6 What Is Love?
+5 The Future
+4 Chikyuu wa Kyou mo Ai wo Hagukumu
+3 Eighteen Emotion
+2 Date ja Nai yo Uchi no Jinsei wa
+1 Romance wo Katatte

+10 1億3千万総ダイエット王国
+9 裸の裸の裸のKISS
+8 TIKI BUN
+7 永久の歌
+6 背伸び
+5 ロマンスを語って
+4 What is Love?
+3 Password is 0
+2 笑顔の君は太陽さ
+1 地球は今日も愛を育む

I'm basing this on how much warmness does the song give to me, so it's not exactly exactly the same as my "favourite songs", there are also the corcumstances that count.(for example, there are much more Ju=Ju songs that I love, but sometimes the circumstances didn't make it for me to put more attention on them)
Anyway, here it goes:

+10 時空を超え 宇宙を超え (Toki wo Koe Sora wo Koe)
+9 君の代わりは居やしない (Kimi no Kawari wa Iyashinai)
+8 What is Love?
+7 The Future
+6 裸の裸の裸のKISS (Hadaka no Hadaka no Hadaka no Kiss)
+5 笑顔の君は太陽さ (Egao no Kimi wa Taiyou sa)
+4 ロマンスを語って (Romance wa Katette)
+3 おへその国からこんにちは (Oheso no Kuni Kara Konnichiwa)
+2 ミステリーナイト！ (Mystery Night!)
+1 I miss you

And of course, there are also:
Love take it all
1億3千万総ダイエット王国 (1-oku 3-senman Sou Diet Oukoku)
Password is 0
TIKI BUN
シャバダバ ドゥ～ (Shabadabadoo)

+10 1億3千万総ダイエット王国 (1-oku 3-senman Sou Diet Oukoku)
+9 Love take it all
+8 愛はいつも君の中に (Ai wa Itsumo Kimi no Naka ni)
+7 時空を超え 宇宙を超え (Toki wo Koe Sora wo Koe)
+6 心の叫びを歌にしてみた (Kokoro no Sakebi wo Uta ni Shitemita)
+5 永久の歌 (Towa no Uta)
+4 The Power
+3 大人なのよ！ (Otona na no yo!)
+2 I miss you
+1 TIKI BUN

+10 キラリと光る星 (Kirari to Hikaru Hoshi) Morning Musume
+9 木立を抜ける風のように (Kodachi wo Nukeru Kaze no You ni), Odatomo
+8 I miss you C-ute
+7 愛はいつも君の中に (Ai wa Itsumo Kimi no Naka ni) Berryz
+6 裸の裸の裸のKISS (Hadaka no Hadaka no Hadaka no Kiss) Juice=Juice
+5 おへその国からこんにちは (Oheso no Kuni Kara Konnichiwa)
+4 シャバダバ ドゥ～ (Shabadabadoo)
+3 The Power C-ute
+2 1億3千万総ダイエット王国 (1-Oku)
+1 背伸び Senobi Juice=Juice

I tried to be really balanced. Although S/mileage didn't make the cut... they've had a bad year imo. Last year they were awesome. This year... meh...

+10 What is Love? (MM'14)
+9 TIKI BUN (MM'14)
+8 時空を超え 宇宙を超え (Toki wo Koe Sora wo Koe) (MM'14)
+7 笑顔の君は太陽さ (Egao no Kimi wa Taiyou sa) (MM'14)
+6 君の代わりは居やしない (Kimi no Kawari wa Iyashinai) (MM'14)
+5 Password is 0 (MM'14)
+4 明日を作るのは君 (Asu wo Tsukuru no wa Kimi) (MM'14)
+3 永久の歌 (Towa no Uta) (Berryz Koubou)
+2 ロマンスを語って (Romance wa Katette) (Berryz Koubou)
+1 嗚呼、素晴らしき日々よ (Aa, Subarashiki Hibi yo) (Sato no Akari)

I really had to think about this. There were actually a lot of really good songs this year.

+10 - Toki wo Koe Sora wo Koe (Morning Musume)
+9 - Mikaeri Bijin (Morning Musume)
+8 - I miss you (C-ute)
+7 Waraenai Hanashi (Morning Musume)
+6 Senobi (Juice=Juice)
+5 Kodachi wo Nukeru Kaze no You ni (Odatomo, pretty sure I'll be the only one with this on the list)
+4 Chikyuu wa Kyou mo Ai wo Hagukumu (S/mileage)
+3 Ai wa Itsumo Kimi no Naka ni (Berryz)
+2 Hadaka no Hadaka no Hadaka no Kiss (Juice=Juice)
+1 Watashi wa Watashi Nanda (Morning Musume)

First year S/mileage made the cut

+10 TIKI BUN - Morning Musume.'14
+9 ミステリーナイト！ (Mystery Night!) - S/mileage
+8 時空を超え 宇宙を超え (Toki wo Koe Sora wo Koe) - Morning Musume.'14
+7 What is Love? - Morning Musume.'14
+6 地球は今日も愛を育む (Chikyuu wa Kyou mo Ai wo Hagukumu) - S/mileage
+5 見返り美人 (Mikaeri Bijin) - Morning Musume.'14
+4 背伸び (Senobi) - Juice=Juice
+3 君の代わりは居やしない (Kimi no Kawari wa Iyashinai) - Morning Musume.'14
+2 嗚呼 すすきの (Aa Susukino) - S/mileage
+1 Password is 0 - Morning Musume.'14

AyuHikaru wrote:+5 Kodachi wo Nukeru Kaze no You ni (Odatomo, pretty sure I'll be the only one with this on the list)

Actually you are the 6th person with that on their list so far =)

+ 10 Towa no Uta
+9 Senobi
+8 Toki wo Koe, Sora wo Koe
+7 Egao no Kimi wa Taiyou sa
+6 The Future
+5 1 Oku 3 senman Diet wo Oukoku
+4 Koiseyo!
+3 Aa Susukino
+2 Watashi wa Watashi Nanda!
+1 Kaze ni Fukarete