I've been working on my Trek DVD sets a lot. For close to 7 years I've only owned seasons 1 and 7 of TNG, but I kept up with all the movies. Than the past year or so I've gone nuts picking them up used on eBay and Amazon. Here's my collection so far:
TOS Seasons: 1 and 2, in the old box set that splits down the middle vertically. Hunting for the matching season 3 set for cheap.
TAS Seasons: 1
TNG Seasons: 1, 2, 4, 6, 7
DS9 Seasons: 1, 2, 3
VOY Seasons: 1, 2, 5, 7
ENT Seasons: 1
So I'm getting fairly close to completing everything finally. Enterprise is prolly my favorite series, but good god the Enterprise box sets (barring season 1) are really expensive, at least 40 or 50 bucks per season, compared to all the others I can pick up around 30, and usually I find them closer to around 25. Also, my first TOS season was 2 in that split box, so I've been trying to get the other two seasons in that same style to match. I finally got season 1 fairly cheap (23 bucks) but season 3 has eluded me for a decent price thus far.