I own both, so can give feedback on my experiences.
I'm guessing that you intend to use the console on your wireless, seen as you post mentions that, so you'll have to fork out £70 for the Microsoft adapter (I'm guessing it's still this much), or nothing for the PS3.
If you can get HDMI to DVI the PS3 should connect through that, the 360 can go through VGA using an extra cable, although this will be another extra cost, but hey, so would be buying one for the PS3. From my experience with using VGA on my original 360, it gave a much clearer picture than component.
Both the 360 and PS3 have the games you like, Halo really is a 'meh' game for me though, totally overrated and not in the least bit what you'll expect, unless you have played one of the series before!
As for a broad range of games, again both have them, the 360 more so, but that is simply down to having a larger back catalogue - it was out for a year before PS3 came along, and if the PS3 really is so difficult to program for; it probably scares off some of the lazy development houses. The pre-owned market is pretty much just as active for both consoles though, but again, the 350 probably has more choice; not to say it’s the better choice though.
A couple of things you haven’t asked, but I feel are important factors, although some may be subjective:
The 360’s hardware has an atrocious failure rate – there seem to be any number of faults it can suffer, from the mundane (DVD drive issues) to total system bricks, also know as the RROD (red rings of death).
The 360 is considerably louder than the PS3, so if you’ll be playing in close proximity to the console itself, you WILL notice the 360; installing games to the hard drive sadly doesn’t quieten down the cooling fans!
Unless you have an endless supply of AA batteries, you’ll have to pick up a play and charge kit, this include a replacement rechargeable battery pack and charging cable, so that it mimics what you’ll get from the PS3 as standard. An alternative and the one I went for is to have 3 rechargeable batters and a charging cradle – but again these are all extras that will cost you; being as they’re official Microsoft things!
You will have to pay for the privilege of playing online with your 360, but thankfully there are places to get membership for an acceptable price – what ever you do
DO NOT sign up via your console with a credit card; as you’ll have a whale of a time trying to get Microsoft to remove it, maybe even end up like a friend of mine and still get bill for another year of Live.
The PS3 often requires mandatory installs on games, and some of these can take ~10-15 minutes, but if you have come from PC gaming, as I did, you probably won’t be bothered by them.
The PS3’s online currently is not on par with the 360’s, if you’re used to such things as private chat (aka cross-game chat), then get ready to be disappointed; I have no idea if/when this will be added, the last thing the PS3 did get in this area was cross-game text! sarcasm “Woo. Hoo.” /sarcasm.
The PS3 has a built in Hi Def media player, so if you have a HD television in the house, you can enjoy Blu Ray movies.
What else is there…. ? I think that’s about all you need to know to help you decide, you’ll probably see something else soon, a fan boy jumping on this post and nit-picking, they’re always good for a laugh though
In my opinion , there is a small difference in some games and I think the PS3 has the edge , although only slightly.
.