cell survival assays

[George Carystinos]

I was wondering if anyone would know what is the best
assay to determine cell survival in mammalian cell lines. 
We are working on various cancer lines and also HeLa and 
cos-1 lines, and we currently use the MTT assay, which is 
very time consuming and labour intensive.
Has anyone used a tetrazolium assay instead? Are there
any other more accurate or quick assays to use?
Any suggestions will be appreciated.
Thank you.
George Carystinos
McGill pharmacology, Montreal
gcarys at po-box.mcgiLL.ca