There's the one and only AMD ATI left. For catalyst-rt, it's a sad case
since catalyst itself is a sad case. Apparently, the xorg team has been
doing a wonderful job with xf86-video-radeonhd.
For non-discrete solutions, it seems the latest Intel offering offers a fair
performance chart relative to mobile nVidia, ATI, SiS and others. No
problems with drivers there although xf86-video-intel needs some smoothing
out.
I switched from nVidia to ATI back in 2006. I then went on to use an older
laptop with nVidia's mobile 440. From 2008 I've been with an Intel-based
laptop (GMA 950, 945 chipset) while the two family desktops at home are
running GeForce 7800GT and Radeon X800GT respectively.