So I'm completely bias as I'm a Mozzer and one of the Mozzers who runs MozCon.
With that said, MozCon is definitely my favorite conference. Last year was both the first year I helped run MozCon and the first year I attended it. I knew all the pieces, and I was blown away by the caliber of the content and the speakers. The topic runs a little intermediate advanced, especially if the topic is primarily SEO-focused, and the speakers themselves are incredibly smart and true experts in their topics. Most conferences to me are really hit or miss, but MozCon was one where I felt that I learned at every session. (I've been in the industry for 6 years.) The single session, one room format with keynote-style talks really suites my learning style and my need for community (live-tweeter right here). (And Seattle is awesome!!)
My second favorite one is SearchFest PDX. Their speaker quality is superb. Though you have to pick between sessions. I found the community pretty great here too. And the year I went, it was right by the food trucks which I can't stay away from in PDX. I felt the sessions were really tailored by topic so you could chose to go on the track you knew and learn something or skip around to learn something new.
If you want to talk to Matt Cutts or get all fannish around him, SMX is the conference to go to. As except for the "celebs" of search or a specific keynote, it's panels, speakers get less time to talk, which I go back and forth how much I like that. I find panels, due to the sheer numbers of speakers a conference organizer must find to talk on a similar topic, can sometimes be a large hit or miss between speakers. And they can also crash quickly if the moderators aren't on top of it.
SES has been a bit more a beginner's conference in my mind. I've found a lot more SMB and SEOs starting their careers going to these than other conferences. It's all panels with a few exceptions like SMX. Both SES and SMX accept pitches, and sometimes, you can get some rougher talks due to beginning speakers. (We ALL have to start somewhere!)
I haven't been to PubCon or any of Distilled's conferences (SearchLove, LinkLove), though I've heard PubCon to be more like an SMX and SearchLove to be closer to MozCon in styles.
Anyway, hope you found that useful. Feel free to ask about specifics you're considering, and really, I can answer about anything about MozCon.