Protection against deer ticks and mosquitoes for seven hours or more:
"recommended"  from Consumer Reports:
 
Off Deep Woods Sportsmen II; 30% DEET; cost: $1.25 an ounce.
Cutter Backwoods Unscented; 23% DEET; cost: $1.33 per ounce.
Off FamilyCare Smooth & Dry; 15% DEET; cost: $1.63 an ounce.
3M Ultrathon Insect Repellant 8; 25% DEET; $1.67 per ounce.
Repel Plant Based Lemon Eucalyptus; active ingredient oil of lemon eucalyptus; cost: $1.94 an ounce.
Natrapel 8-Hour with picaridin; 20% picaridin; cost: $2.00 an ounce.
 
Others tested included:
Avon Skin-So-Soft Bug Guard plus IR3535 Expedition SPF 30, active ingredient IR3535; cost: $3.50 per ounce.
Bite Blocker Xtreme (organic); Plant oils active ingredient; cost: $1.34 per ounce.
Cutter Skinsations Clean Fresh Scent; 7% DEET; cost: $1.04 per ounce.
Burt's Bees All Natural Herbal; active ingredient plant oils; cost: $2.00 per ounce.
 
DEET?
Environmental Protection Agency (EPA) has judged DEET to be safe when used as directed, but that it has caused rare toxic reactions when not used as instructed. The EPA also says DEET shouldn't be applied to babies less than 2 months old. The American Academy of Pediatrics has advised against using repellents with DEET concentrations higher than 30% on any kids.  Consumer Reports Health says no one should use a repellent with more than 30% DEET.