Broken Base: There are fans who think the group's switch to King Records made them more "mainstream" and think their older singles were much better. Then on the other side you have the fans who think the sellouts prove that AKB is finally getting the attention they deserve. And then you have everyone in between.
Also, many fans from AKB's Golden Era are quickly leaving the fandom now that older members are graduating and younger members from sister groups start taking the spotlight.
Opinions of the former members that ended up in porn industry such as Risa Tachibana and various members that formed Honey Popcorn.
Ensemble Dark Horse: Amina Sato. For someone who is neglected by the management, consistently placing in the top 21 for senbatsu elections is surely something. However, she dropped to rank 33 in the 5th Sousenkyo, but that makes her the Center of the Next Girls.
Some really popular members from sister groups, like Jurina Matsui or Sayaka Yamamoto.
Miyuki Watanabe was unranked in 2011, then suddenly shot up to #19 in the 2012 election and raised to #15 in the 2013 election. However, her popularity decreased after she was involved in a scandal, with most of the NMB fans votes going to Yamamoto instead.
The Team 8 as a whole. Originally planned to be just a publicity group to be only involved in Toyota events, the girls' youthfulness and talent made them extremely popular among AKB fans. They are now a solid group who acts in concerts of their own, and have original songs featured in AKB singles.
As seen in the Hilarious in Hindsight entry below, the very notion that Sashihara Rino would ever win the Sousenkyo was a running joke since nobody saw it coming. Let alone winning four times after a major scandal.
Atsuko Maeda. Probably the most promoted member of AKB48. She's the center for almost all AKB48 singles to date.
After her graduation, despite Yuko being named new leader of AKB, Haruka Shimazaki has taken Acchan's place in most promotions and songs she was featured in. Also Minami Takahashi is the member who represents the group in TV programs and interviews. Yuko keeps the center in AKB-exclusive events and concerts.
After Yuko's graduation, and since she ranked #1 in the elections, Mayu Watanabe became the face of AKB until she graduated.
Fandom Rivalry: With Morning Musume fans. However, some members of AKB48 are fans of Morning Musume and vice versa. There are even some members (ex: Yuki Kashiwagi) who auditioned for Morning Musume.
Manami Oku, often forgotten former original Team K member, is surprisingly popular with JKT48 fans. There are Indonesian fanclubs dedicated to her, and most of the comments in the videos/pictures related to her are made by Indonesian users.
Haruka Nakagawa was moderately popular during her AKB days, but her career really took off after she transferred to JKT48. She became fluent in Indonesian, stays in Jakarta after her graduation and regularly appears in prime-time television shows to this day, and occasionally also does work in her home country. She was also appointed a Goodwill Ambassador for Japan-Indonesia diplomatic relations.
Hilarious in Hindsight: In 2011, AKB had this comedy show called Bimyo, and the first episode had a skit in which Sashihara was the group's center. The idea was ridiculous at the time. Fast forward to 2013 though...
Same with an episode of the variety show Mechaike in the same year, where Okamura declared that Sashihara would never become center.
Seeing your oshimen being sliced and diced in the original uncut PV for "Beginner".
No Such Thing as Bad Publicity: Sashihara took a hit to her career when an alleged ex-boyfriend sold her out to the media by sharing intimate details about their relationship and sex life. A few years later, she came in first in the rankings and even (sarcastically) thanked the tabloids for running the story.
Portmanteau Couple Name: Over the years, plenty of members who are close friends are called these: AtsuMina, Mayuyukirin, JuriMayu, YuiParu, TomuPon, NakoMiku, YuuNaa, Mogion, Yuiyuihan...
Yuko is a surprisingly good actress. Yasushi Akimoto, producer of AKB, said he thinks that she'll be an internationally known actress in 10 years.
One new generation member who has shown exceptional acting skill is Nana Okada. In the TV drama Joshikou Keisatsu featuring Tentoumu Chu!, one episode had dialogue filled with Tongue Twisters. They were so hard, they had to keep looking down at their scripts in front of them. The only who did not have a script and said every line perfectly was Okada.
Another young member who's shown great acting skills is SKE48's Nao Furuhata. Even though she has had no experience in acting, she was the winner of an acting audition in an SKE TV show "Position Zero" and was given a guest role in a serial drama.
Team B's Watanabe Mayu, who has previously starred in several dramas. One role that really shows off her acting prowess is Usa Shijimi/herself in the live-drama adaption of the manga Saba Doru, in which Mayu is actually a woman in her late 30's concealing her age.
After predicting that AKB's popularity will probably wane in 1-2 years, a lot of fans bashed Rino Sashihara for being the "negative idol" and "unsupportive of her group." While the backlash died down, she had to develop a different fanbase of her own, from being in HKT and appointed its manager.
Yui Yokoyama was this when she was a newly promoted member, as she got heavy promotion.
The next scrappy is Miori Ichikawa, transferred to NMB. Many fans believe her cute appearance and behaviour doesn't fit with NMB's more sexy style.
Miyawaki Sakura. Despite being an HKT48 member, she's got a huge push on AKB48 singles, which puts people off. It doesn't help that she is one of the AKB48 ace candidates, despite already being one of the front members in HKT 48.
Vindicated by History: Both Rino Sashihara and Minami Minegishi were "demoted" from their regular positions in AKB due to scandal—but LOOK WHERE THEY ARE NOW.
Sashihara was sent to HKT48 in 2012, which was the then-newest sister group only in its second year. Many thought this to be like an "exile", but Sashihara utilized her seniority and experience to help mentor the young HKT members, as well as promoting them on TV shows and other media. In the 2013 General Election, she pulled a Dark Horse Victory and won first place, beating Yuko Oshima and Mayu Watanabe! She also shares a concurrent post as a theater manager for HKT.
Minegishi, a first generation member, was demoted to Kenkyuusei in 2013, and it didn't help that her public apology in which she shaved her head sparked a controversy that even reached international news outlets. But like Sashihara, Minegishi was put in a unique position to be a mentor to the Kenkyuusei, who were made up of the newest and youngest generations of AKB members. This allowed the group to polish their skills and coalesce into a performing team that would attract more interest in fans wanting to see their theater shows. In August 2013, the 13th and 14th generations were all promoted to Team 4, with Minegishi as team captain. Their first original song as a team, "Seijun Philosophy", ranked #1 at the 2014 Request Hour. Minegishi stayed as captain of Team 4 until 2015, where she is now captain of Team K.