I decided to make this page, since I tend to go to other cons (especially in 2010 on up). Hopefully, it'll help you with deciding which con to go to by giving my opinion.
Links are provided on the images.

This is the con of cons to go to. Everything from the incredibly large dealer's room and artist alley, to the gaming rooms, to video... you can easily get lost in all the chaos. Typically cosplay is mostly geared right, with a lot of opportunities to take photos. Always something fun at this con, but can break your bank. The con calls home (for now) the Hilton Anatole.

Pros: HUGE, ENORMOUS con. Plenty of dealers and artists here. Anime is the primary theme for this con, but cosplay is mixed.

Cons: Wait times for certain events (especially BADGES) can be borderline infuriating. A few of the volunteers -can- be anal-retentive.

Don't go if: you get claustrophobic or d
AKA "A-kon Lite," this con typically hosted to a smaller audience. Unlike A-kon, this con is non-profit, so visits can vary depending on what you're looking for. Ever since the move to the Sheraton (where A-kon used to be), the con is trying to appeal to a less "targeted" audience, and is becoming an anime con-goers worst nightmare: An anime con showing Disney and US cartoons. Also home to AnimeHell.

Pros: Smaller con, easier to navigate. Easy access to food via Plaza of Americas. 2014 introduced mailing of pre-reg badges. AnimeHell

Cons: Small dealer's room with a "general" flavor. Video rooms showing kids shows (ie Disney) in prime-time. Too geared to the raves and concerts, and suffering elsewhere. Cosplay sometimes is good, sometimes beyond horrible.

Don't go if: you're looking for rare gems or preview anime here.

EDIT: Last heard the con is under new management, will go again in 2017 to see if it's improved.
Small con nestled in the best place in OKC, but what it lacks in attendance, it has in support. Mostly fan-based, it is a good place for rare gems and watching decent anime picked by the fans themselves (seriously, they ask attendees what they want to see in the Video Rooms!). The Dealer's Room is small, but well-packed with good taste, with a few eclectic things thrown in. Cosplay is really good, and is situated between several hotels.

Pros: Smaller con, easier to navigate. Great access to hotels, shops, and food (thanks to the OKC underground). Rare gems can be found. Also, Video Rooms are fan-oriented, and the cosplay is really well-done

Cons: Small Dealer's room. Not typical to see new anime premier here (but did see some new items like the Oculus Rift).

Don't go if: you want to spend a lot of money. 
A literary con with few highlights for those not interested in buying books (yes books). VERY small dealer's room, no video rooms. Gaming is decent here, but the highlight I'd love to recreate at other cons: MST3K Friday. Guy brings in two B-movies for the audience to enjoy and make fun of. ZERO cosplay.

Pros: MST3K Friday

Cons: Book fair, no movies/TV/video games.

Don't go if: you expect movies/TV/video games
A horror con that lives up to its namesake via the staff. The stars attending are top of the line for their field, and some movies show (usually after 6pm). Can get to see sneak-peaks of never before released horror films and talk to stars. Cosplay is spotty.

Pros: Big name stars, lots of memorabilia, get to watch movies not even at the theaters.

Cons: Staff is MAJORLY anal-retentive to the point of madness, and heavily disorganized. Confusing (and EXPENSIVE) badge prices/perks. Be prepared to drop a few hundred on signatures (hey, the stars gotta eat too). No badge, just a cheap wristband. If you go (and didn't buy the $200+ badge 7-8 months in advance), make SURE you find out about how to buy the ticket for the special guest (the year I went was John Carpenter).

Don't go if: You get mad easily, or broke.
Nestled in a small college in Stevenville is this little con. Seriously, it is small. You won't believe how mind-blowingly minute it is. I mean you think going to the front door is a small step, but that's NYC compared to this con... ok, I'm para-phrasing. Basically this con is solely for those who are desperately wanting to go talk with like-minded people. Video rooms are a converted lab, and the sound bleeds over each other. The dealers room had 3-4 dealers, selling very little. No games, -very- little cosplay... and just to get there you have to circumnavigate Tarleton State (it is the only con I have been to NOT held in a hotel). There are no cars allowed on campus, so you have either the football/admin parking and a ten-minute walk, or parking to the south and a 5 minute walk. Seems the only highlight I saw was more trying to get people to register at Tarleton State.

Pros: Good people. Only highlight is the Science lab had a "Mr Wizard" style exposition.

Cons: Not held in a hotel, so parking's a pain (Nearest hotel is 5 minutes driving distance). Video rooms set up in a science lab, with no division and the lights on (They use Crunchyroll and Netflix for their anime, ie you can watch these at home). Jokingly small Dealer's Room. Little cosplay. Basically looks like an excuse to go and take over a building to watch anime on the college's dime.

Don't go if: You don't go to Tarleton State.

Another con hosted in San Antonio, a con I'd compare equally to A-kon, but further south. The staff is quite helpful, cosplay is plenty, and sizable Dealer's room. One of the highlights was something A-kon used to have: a full arcade with FREE arcade games. Also nice is it's walking distance from the Rivercenter Mall, and historic areas (including the Alamo).

Pros: Bigger convention, friendly staff, easy access to food, hotel has free wifi, cosplay is great, and nice scenes for pictures. Also great arcade room (with FREE games).

Cons: Free Wifi is spotty, especially in the evening. Hotel staff can be a bit anal (with -very- good reason, so quite minor), humidity due to vicinity to the Riverwalk, and.... the DRIVE (for me at least).

Don't go if: You have major sinus issues.
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