In my apartment, I have a Belkin 802.11a/b/g router connecting me to my cable modem and (thanks to TiVo Desktop and my dual-boot MBP) my TiVo. Despite a warning from my dad that it might not be the most reliable brand out there, it has performed rather well. Occasionally it will have a fit and not let my computer or my roommate's (12" PBG4) connect- I usually solve this by waiting for it to pass, changing the WEP password, cycling the power, or hanging the router from the gallows pole (note to self- explore Led Zeppelin theme).
My previous machine, a 12" iBook G3 700Mhz, suffered through the above router problems, but what it did do was reliably connect to my preferred home network without assistance from me, as long as Airport was on. When the computer turned on, or woke from sleep, it connected automatically. I saved the password in the "NYC Apt" location in my Network preferences.
when I migrated to the MBP, the computer worked great except that, on system start, wake from sleep, and turning airport on and off, I had to manually select the network, but not re-enter the password. I finally deleted the preferred network from the Network control panel, and now it connects fine. The stored item in the control panel seemed to have been conflicting with the stored password in the keychain. Only time will tell whether I will have to enter my keychain password every time I want to connect to the wireless network...though Gmail Notifier has my Gmail password stored there as well. But for now, success