General rule is the better the media the less problems you will have. So avoid `cheapies` unless you are certain of the quality or your DVD-RW is known to be happy with them.
I use TDK generally but I have used Phillips and Imation as well.
As for +/-R it is personal choice and what your DVD player will accept. Most DVD players accept +R but I had one that didn`t. With -R you must remember to finalise the disc or it will not play in another DVD.