When talking serious 4X4, you can't beat the Jeeps. Don't get a Liberty or anything with a V-type engine. The inline sixes are where it's at. If you want to save some gas (and money), the 4 bangers will do anything you need them to do. If you are buying new, GET LIMITED SLIP. I can't stress this enough. My mother ordered her 92 cherokee with 2 open diffs (4.0L, 4 spd automatic, 3.23ish gears), and if you are going over anything other than dirt, you'll slip. Sand, mud, rocks, deep snow all bog it down and make it jump sideways.
I work as a valet, so I can give you the lowdown on pretty much any SUV that you'd like to buy. I'll tell you that the Land Rovers have the worst turning radius of any vehicle I've ever driven. I mean, it's so bad that it's actually noticeable compared even to fullsize Suburbans and Yukons.
My pics, if I were to get a new SUV:
small:
Jeep Wrangler (4.0L)
Honda CR-V
Medium:
Chevy Trailblazer
Ford Explorer (meh, it's OK)
Large:
Suburbans, escalades, yukons, etc (they're all essentially the same)
Infiniti QX-4
The biggest problem with jeeps nowadays is that you can't buy the 4.0L with a manual transmission anymore...at least it's not offered as an option, you might be able to special order it. If you want row-your-own, go with the 4 cyl. Like I said, plenty of power. Since it's going to be a kid hauler though, I'd highly reccomend getting both a hard top and an automatic, so you have just one less thing to deal with. Also, loading baby seats into and out of the back of a wrangler gets kinda hard - a 4 door vehicle might be best. If you're going that direction, you should go GM. Personally, I loathe GM cars. I think that they are the worst made POS machines I've ever seen, driven, owned or ridden in (and I've owned a few), but their SUV's and trucks are second to none. Well, second to Ford, but at this point, it's pretty much tied neck and neck.
The reason I listed the CR-V is that it offers more creature comforts than the Wrangler (good for kids), drives kinda like a wrangler and offers 4WD, and it has 4 doors. However, for simple fun factor, you can't beat a Jeep. Period.
And just so you know that i know what I'm talking about, I've been around Jeeps my entire life- I was brought home from the hospital in an 83 CJ-7 that my father still has (and I'm collecting parts for a restoration soon), My dad's driven Jeeps since 1970, my mom's had Jeeps since 1985, and out of the 7 cars that my family now has, 3 are Jeeps, 2 are trucks and 2 are cars, all of different makes and models, from different years. As a valet, I drive everything from $300,000 maseratis to overheating rusted out 92 Berettas (yeah, it's true).