Legend of Zelda link to the past is clearly the best..
But I like a lot of games, quite a bit and not good at choosing ranks so I'll just sorta ramble off a bunch of memorable games I really enjoyed:
Any other Zelda series game though is good to(played beat them all several times.. accept the 2nd.. I hate side-scrollers - tis no my cup of tea).
Of rpgish like games, I liked the Mana (Legend of Mana ftw) series, The final fantasy Series up until 12 (5 being the best I think), sorta excluding 11 and 10(though 10 is playable:P.. never touched 11). The Suikoden series, more so 1 and 2 - were really good. among many others.. (Breath of Fire1-4, Summoner, Paper Mario's, Crystalis, Phantasy Star 1-2(never got to playing 3 and 4 yet haha), Dark Cloud, and Golden sun 1-3 to name a bunch more great ones)..
Of RTS's I've always liked Warcraft 2 - Age of empires 1-3 were all good but played far to much of 2... far far to much.. Stronghold was pretty decent as well. I'mma throw Ogre Battle MotBQ and 64 in this to. Very fun games. sorta rts but a lot different then an RTS at the same time.
Harvest moon! .. Primarily Harvest Moon friends of mineral town, none of the others compare to its addictiveness... So many hours gone ... But all the others I played were pretty fun to.
All The Dynasty Warriors games, from 2 - 5 were fun, though Dynasty Warriors 5 empires is the winner of that group - again.. so many hours..
For Turn based .. Final Fantasy tactics, and Tactics Ogre were pretty fun, as are the Advance Wars games.
Towns is a pretty good one to, I don't know if you guys have tried it.. - so many hours already.. and probably to many to waste coming haha.
And also, Legend of Zelda A Link to the Past, again is the best of course

if I didn't say it...
I am probably forgetting a bunch here at any rate.. err.. yeah..