Steve Kilts' Advanced FPGA Design is good on tradeoffs between time and space - he works through examples where he optimizes for each. Chandra Thimmannagari's

Steve Kilts' Advanced FPGA Design is good on tradeoffs between time and space - he works through examples where he optimizes for each. Chandra Thimmannagari's CPU Design has a chapter on Verilog with many instructive short but nontrivial examples, in a novel compact format.