The standard Goblin only carries a squad of infantry, so it's not going to move masses of troops for you. The Maxim will carry a full platoon, but it's got terrain limitations due to its hover movement. Badgers are noted to be tough to kill, and can carry two full platoons of grunts, although they tend to get immobilized easily.
In terms of NON-independent transports, the standard array of Heavy APCs will haul a full platoon each, and are armed with a variety of light anti-Mech, anti-vehicle, or anti-personnel weapons (LRMs, SRMs, or MGs). While none of them are a dire threat to a 'Mech or combat vehicle by themselves, they've got the armor to withstand a hit by most weapons and keep going, and can at least shoot back. You'll want to escort them with something better armed, but they're durable and effective for their miserly price or point value, not like using flatbed trucks to haul PBIs and getting a full company of men annihilated by the first Locust or J. Edgar that makes it past your escorts. Of course, if deployed in sufficient mass, getting shot at by 4-12 LRM or SRM launchers at once can make an opportunistic opponent sweat the die rolls. Personally, I'd rather dump points into a company of Heavy APCs with LRMs or SRMs than buy a couple of LRM or SRM carriers that will die in the first round of fire.
