I have been using the wrt54gl for a few years now, and would like to upgrade to a 802.11n-capable router. It shouldn't be too expensive, and have a similar support in the hacking community as the wrt-series routers did. Firmware I would like to be able to run would include openwrt/dd-wrt and maybe Tomato. Maybe someone could make a few recommendadations?
I, too, have been looking for a good 802.11n-capable router to put OpenWrt on, and this Buffalo device is looking promising. Quoted from the OpenWrt wiki page I linked to:
Status: Working (Backfire 10.03)
As of July 2010, this router is available in the US for around $80. It has tons of flash and plenty of horsepower to handle a lot of bandwidth (at least 25Mbits bidirectionally based on some users' testing). It is easy to flash and hard to brick. Quite possibly the best gigabit-capable router that OpenWrt runs on at this point.
It turns out that the Buffalo WZR-HP-G300NH comes with dd-wrt as the stock firmware. No need to wonder about compatibility, or worry about bricking.
I have a Netgear WNR3500L, which can run Tomato as well as DD-WRT and OpenWRT, and has 802.11n wireless (not dual band though - I don't think there are any that have that).
You can also look at the Asus RT-N16, which has more memory. I cannot remember the reason why I went for the Netgear instead.
I prefer Tomato as I could not get QoS working on DD-WRT. Tomato also has just about evrything I would want and has nice bandwidth graphs. The only things I miss is VLAN sections in the web-interface and Dual-SSID.
You can see on this page that there are many Linksys models that have 802.11n and are supported by DD-WRT, but not Tomato. I'm not sure if they have OpenWRT support.
I got a re certified Linksys WRT160NL straight from Cisco, installed DD-WRT, and it's been rock-solid ever since.