That game hasn't aged terribly well. It still looks good, but gameplay-wise it kind of annoys me. For one, Monica doesn't measure up to Max --- she can, but it takes way too much time and effort. The monsters can be good, but the fact you can get Steve's (awesome robot name) best equips by the 3rd chapter kinda makes it hard to bother caring for Monica's Monster Haps. Also, and this is a big one, I hate the projectile attacks, they're just waaay too weak.
Actually, you can't fix Monica's Monsters because they are just that bad. The biggest upgrade for them doesn't come until you've completed the photograph sidequest which only happens around either the very end of the main game or during the post game dungeon (provided you haven't missed too many pictures to begin with; like 7 is the limit) which doesn't even start with Monica to begin with; you'll only get her half way through it, and by that time Max is working on his ultimate weapons and Steve is fully maxed out (and even after level grinding the Monsters to max level, they're still garbage compared to literally everything else (including Monica's Bands which have probably fallen behind as well since the NPC who boosts the exp gains for the Band weapon type is only available for a single chapter during the early-middle part of the game).
Anyways, I got to the end of Chapter 4 in VP2 and goddammit, I'm right back where I started. Time to go back to the PotVD and grind out at least 4 (if not 6 or 7) more levels for both Dylan and Lezard (there is literally no good level grinding spots between the end of Chapter 3 and the start of Chapter 5; just a couple of generous boss fights, an old dungeon restocked with new enemies, and a new dungeon that's six screens long, and neither have Geysers). At least I confirmed that I'm going to get the Tri-Emblem.
Anyway should I get Paper Mario or Super Mario RPG!!?!?!??!
Paper Mario and Super Mario RPG are surprisingly rather different games. SMRPG is more like a SuperNES era Square RPG with Nintendo characters/setting and is longer and more convoluted of the two games (but only about as long as an average SuperNES era RPG got, but nowhere near the grind).
Paper Mario is a lot more direct in many ways, its a shorter game, has less numbers p0rn that Square/Squeenix loves to death, battles consist of only Mario and a single companion out of half a dozen or so, less difficult navigation on the field, plot's a bit drier and less involved, equipment choices are limited to two options with fixed upgrades plus badges that can be equipped for different effects, only three actual stats HP, FP (i.e. MP), and BP (Badge Points for equipping badges) with the interesting ability to pay a guy to rebalance them so that you can have whatever build you want.
Both games though have turn based combat that feature timing based command inputs to influence how much damage you deal/receive (with SMRPG being the first CRPG to implement it) and field maps that incorporate platforming elements. I'd say get them both, but ultimately the choice is yours.