I think they're all pretty decent. (HP, Dell, Gateway, etc.). I would stay away from Sony though (way overpriced). Also, HP/Compaqs come with a LOAD of crapware in them preinstalled.
Vista versions, I would go for vista Home Premium. Windows 7 isn't officially released yet.
If you are getting Vista home premium, 2 gigs of RAM minimum. Most have at least 2 gigs nowadays but some are sold with vista home premium and 1 gig of RAM. Trust me, vista home premium should have 2 gigs (especially if you don't know how to tweak windows). If you go for Vista Basic, 1 gig should suffice.
You should get a windows OS recovery disk(s) with it. nowadays, companies like HP/Compaq just store the backup windows OS files on a separate partition on your HDD and windows will come with a program where it lets you burn the windows recovery discs onto your own DVDs. (When I got my laptop, I just called up HP and they sent me the recovery discs free of charge.)
MS office (word, spreadsheet, etc.) is installed on all vista OS's as a free trial. (like 60 days or so). then you'll have to pay after that or use something else.
With routers, Linksys is pretty popular. Some ISPs give them to you for free as long as you use them as your ISP. (I love my Verizon VIOS router from my Verizon ISP.) Most have hardware firewalls nowadays. And just about everyone of them has wireless capabilities.