[quote name='DarkKenpachi']2. I got a few Lego Star Wars Sets for myself
Should I get the Battle of Endor set? and Darth Vader's Tie Fighter? and which Lego City Sets do you recommend?
collecting for yourself is one thing, and buying for children is another.
kids will remove minifig heads with their teeth (no matter how many times you tell them to twist them off instead) and other bricks and pieces will take their abuse. since you had lego as a kid, i'm sure you know what i'm talking about.
since you already have your childhood collection to get them started, you may not need to pick up a few basic brick boxes (on sale, of course). i always buy whatever i find on *deep* sale and just dump in the big bin. my boys use the pieces to make their own ships, buildings, layouts. they can tear apart "real" SW sets to make new ships, but they can also use space police, atlantis, exo-force, whatever. kids dig quantity .. the more pieces they have, and the greater variety, the more creative they'll be. and they can play with their friends because there's enough to go around.
we bought the wheels & axles kit so there would be less fighting over wheels.
re: city sets, small cars and planes and plenty of minifigs are great, but you need buildings too. the baseplate bldg sets (fire station, police station, etc.) are very playable. the kids can use basic bricks to build other buildings and props. we have the old airport set (7894) and it's perfect -- very generic, so it can be an airport, police station, mall, jedi temple, anything they want it to be.
so, in summary, for kids (you don't mention how old your twins are), i would recommend a big bin of random lego, at least one major building (which usually come with several minifigs and vehicle(s)), and then add wheels, minifigs, and sale sets as you go.