I find that "snare" spells--which mainly consists of entangle, web, plant growth--really drain the excitement from many fights, often pretty much stopping them before they begin, and there isn't anything that most opponents can do against them in terms of counter-tactics. The bad guys are often hosed right out of the starting gate if they don't beat the caster's initiative roll.
Entangle has a ridiculously large area of effect (16 squares in diameter) easily able to affect every opponent in a unit even they're a bit dispersed. Even those targets that make their save can only move at half speed, and since the AoE is so enormous, that likely means they wind up having to make a second save. Sure, it doesn't work on every battlefield, but that's hardly consolation when it does. Lats 1 min/level and can be dismissed at will by the caster.
Web has a smaller AoE, but its effects are even more severe and its applicability extends not just into the wild but into the dungeon as well. Targets that make their save arre still entangled and have to make Str checks just to move a couple of squares--maybe 3 or 4 if they roll well. Lasts 10 min/level and cn be dismissed at will.
Plant Growth is simply insane, and if you don't know what I'm talking about then you've never seen it come into play. If the opponents rely on ground movement (as many foes do) and are ineffectual at range (as many monsters are), they're quite likely finished. No save allowed, no spell resistance allowed, and here's the AoE, for those who aren't familiar with it: a 100-foot-radius circle, a 150-foot-radius semicircle, or a 200-foot-radius quarter circle. The caster can selectively designate areas that aren't affected (which is particularly convenient considering that a diameter of 40 squares almost fully covers most megamats, leaving PC's with no place to stand).
The big problem is that snare spells are effectively "rocks without paper", i.e. the designers didn't build in many good countermeasures against them. The one spell designed to defend against spells of this nature is freedomm of movement. It shouldn't take a 4th-level spell just to protect one creature against a 1st, 2nd, or 3rd-level area-affecting snare. And there's not a lot of dimension-dooring or teleporting at that level either. To tell the truth, I'd rather see bad guys hit by fireballs every round and have to mark off some hits points than to have them bogged down for several rounds.