Hmmm, Sarg, its a bit of a leading question really.......we all have our favourites! Come over to xdrivers.co.uk for a mosey around and some advice - its a very friendly place
This is always just going to be a personal choice and opinion thing, but I looked long and hard before settling on an X5 between that lot you mentioned and the Toureg and Porsche version.
Q7 a very ugly lumbering thing, huge foot print, just as bad as an S8 to park in miserly parking lots. Expensive - don't think the budget you mentioned will get one. Q5 possibly better but also expensive still.
XC90- boring boring boring old gitz car (sorry folks to all the Volvo fans!) Had issues with spontaneous fires breaking out as per Watchdog a year or two ago. Very few toys. Worse than average fuel consumption for a big SUV.
Likewise the older MLs - they come in all flavours these days, but are quite spartan and interior finish of Merc is IMHO nowhere near that or BMW or Audi. Very pricey repairs and prone to early failures of some bit I can't remember off hand.
Touareg - big and heavy, the V10 is very heavy on fuel, but well equipped and nice interior, as is Porsche's SUV - they are both the same, really, and jury out on the looks - a bit like Marmite.
I had a P38 Range Rover for 6 years before my X5 - the Rangey was an expensive beast to keep 100% working and finish was , well, typically poor / typically British, interior not great compared to BMW, but I did grow very fond of the old thing and it didn't let me down.
X5 - only model I ever really wanted was the 4.8iS Alpina-derivative, facelift shape. I hate the "new" shape and won't be getting one as I dislike the shape so much, so when the 4.8 goes, who knows? Having said that, I tend to keep my cars for years, so its not leaving anytime soon if I can help it.
Fantastic engine, cooled with an oil cooler below the main radiator, what a performer, and what a pleasure to drive. Closest drive to the S8 IMO.
Mine is a very high spec model as a few 4.8is were, all the BMW toys
fuel consumption not bad for the big body - around 24-26mpg (I do a lot of long trips). I dislike LPG intensely and prefer to keep the V8 running as it should on petrol, which it quite likes
Great performer in the snow and ice on its winter shoes - Vredestein Wintracs on 18" wheels, usual wheels are OEM 20" HUGE tyres. (315 wide on the rear!) I love the colour - Le Mans Blue - and the gorgeous black special order leather interior. It was also the ONLY SUV to have seats even REMOTELY comparable to the Audi S8, fully adjustable, heated, recaro type, which was really important for us as we both have back problems and I regularly drive very long distances. You could get a 4.8 is in your budget, but the new shape X5s are a bit higher than that still - of all the SUVs, the X5s tend to hold their resdiuals quite well, especially diesels.
*EDIT* Spacious cabin, rather like a large luxury car inside than an SUV, boot space not particularly large, but seats do fold estate-style. Rangey has a much bigger boot.
I suppose the only way to be sure for yourself is to go and look at some of these SUVs and drive them yourself as its a very personal choice!!
Good Luck with the search