[?]Firstly, you may want to change your pipeline. There are more sophisticated approaches for computing coverage using RNA-seq data.[?]
As to your question, the CLC mapper does local alignment (if I am right), while most of the mainstream NGS mappers do glocal alignment. Based on this difference, you can exclude bowtie, maq, soap1/2/3, bwa, gsnap, novoalign, rmap and many others. BLAST is similar to the CLC mapper, but I guess it is too slow.
A few fast mappers do local alignment like the CLC mapper. You may consider bwa-sw and smalt. BFAST may be a viable option, too. I do not know for sure.
[?]In the end, to increase the chance of getting a better answer, you should provide more details about what you are doing. You should also explain why the aligners you mention are "nothing comes close".[?]
EDIT: for your application, you may try bwa-sw and smalt. If the default configuration fails, you may consider to change the parameter to make them more sensitive (for bwa-sw, increase -z to -z10 or so).
From what organism are your reads? What type of reads Illumina, 454, solid? What read length and are the reads paired? This is RNA-seq? And why use NCBI NR?