I've been trying to get FONV to work, but it's just too glitchy, so I reverted back to Fallout 3. After doing everything I felt like, I've done all the main quests and side quests, except Take It Back! and gotten all the Bobbleheads that I care about... The bad thing is, I'm only halfway through level 18. I was wondering if I should buy some DLC so I can get up to level 20 for the perk I want, or if I should just accept my fate as "that guy who didn't get to level 20". I only want Operation Anchorage, maybe Zeta, and definitely Broken Steel (for the extra missions and perks). The question is: Should I just get the GOTY edition for all the DLC, even the ones I don't want?

yeh

You've not mentioned point lookout, it's not one that I like that much but it's worth checking out and playing the missions, you might find you like it lots! The Pitt is one of my personal favourites and both of these DLC provide a nice change in environment and new stories etc. So if you like the vanila game and have the spare cash and are looking to buy a game I think it's worth it.

The only reason I'd want Point Lookout is for the Double Barreled Shotty, which I have The Terrible so it doesn't matter anyway... And the Pitt's rewards aren't all that great either...