I played LotSB last night again as part of my trilogy play through. It's testament to the Citadel DLC that I hold it in an even higher regard than Shadow Broker. Like you said, it helps not to take Citadel overly serious. Once you're ok with that then the rest of the DLC is an absolute delight. It strikes exactly the right level of self-reference and in-jokes. I can see that it might be too much for some, especially if you're a latecomer to the series, but as someone who's been there since the beginning, I absolutely loved every second of it.
I'm not going to lie, I detest the ending. If that had been my enduring memory of ME then I'd have been incredibly disappointed. Luckily, the Citadel DLC gives the series a meta-closure that the ending to the game just didn't provide. Not to me at least.
I doubt that I'll continue with ME beyond ME3 - I've yet to hear a single decent idea about what the next game should be, and in truth they're going to have a hell of a job on their hands to come up with a better set of characters. Plus with production moving from the Edmonton to Montreal team, I'm really not convinced that they'll knock it out of the park. They've done well with the MP aspect of ME3, but Omega was their attempt at SP storyline - as you've already discovered it was fairly plot-lite.
That's not to say that I'm done with ME though. I'm sure that I'll be going back for a few play throughs yet.
I'm also looking forward to seeing what Edmonton's new IP is.