Gneech, marking depends a lot on the class.
Fighters mark when they attack, so they need a thrown weapon (or even, since they mark on an attack, not a hit, a bow to pull out when they need long range marks--wow, a reason for a fighter to use a bow!), but most marks are very weak at range (just the -2, no riders).
Wardens mark adjacent foes, so no love.
Swordmages can -use- their mark at range (and with a feat, that can be "close burst 20", which is usually plenty), but can only mark within a Close Burst 2. Which is curious, there aren't even any feats to extend that burst, though they can get featss that will let them mark two targets within the burst, all targets, etc.
Paladins mark with a close burst 5, and only have to engage the target -- so while they don't have the nigh-unlimited marking range of a fighter, once they've gotten within 5 and dropped a mark down, they can maintain the mark indefinately (as long as they have bolts or amunition or a magical throwing weapon) and it's more effective than just a -2 on attacking anyone except the pally.
Avengers are fine with their ranged attacks. Seriously, I suggest that Avengers take one melee At-Will for their bread & butter attack, but then take a Ranged At-Will for the other one.
This.
The first melee at-will for an Avenger is golden.
The second? Is a power not measurably better than a charge, and not giving you substantial options beyond "charge or mba or primary at-will". Whereas slotting a ranged attack gives you -substantial- choices over what you started with.
Moreover, an Avenger, because they do not have the power to re-purpose their Oath without ending the encounter or defeating the target (or use a valuable level 2 utility that's better spent on a teleport that you'll use every encounter) shouldn't always use Oath at the very beginning of an encounter, as it often takes a round or two to know what the best targets for your oath are. And as long as you're not running Oath, you're better off hitting something at range and maybe splatting a minion, rather then getting mired in melee combat with something that will have friends around to help it.