Dans la vitrine de l’agence, il y a plusieurs annonces, mais celle du rez-de-chaussée me plaît le plus.

This phrase sets the scene: it means in the agency’s display window.

A few useful points:

• dans = in / inside
• la vitrine = the display window / shop window
• de l’agence = of the agency

So la vitrine de l’agence means the agency’s window or more naturally the display window of the agency.

French often begins with a place expression like this before giving the main information:

• Dans la vitrine de l’agence, il y a...
  = In the agency window, there are...

This is very natural in French.

Because agence begins with a vowel sound, French uses elision:

• de + la agence becomes de l’agence

This is the same pattern as:

• le ami → l’ami
• je aime → j’aime
• de le does not become de l’; that becomes du only with masculine singular nouns beginning with a consonant.

Here:

• agence is feminine: une agence
• so de la agence is shortened to de l’agence

Il y a means there is or there are.

In this sentence:

• il y a plusieurs annonces = there are several ads/listings

French uses il y a very often to introduce the existence of something. It is one of the most common French expressions.

Examples:

• Il y a un livre sur la table. = There is a book on the table.
• Il y a trois personnes dehors. = There are three people outside.

Even though il literally means he/it, in il y a you should learn the whole expression as a fixed phrase.

Une annonce can mean an advertisement, a notice, or a listing, depending on context.

Here, because the sentence mentions l’agence and a display window, annonces most naturally means property listings or ads posted in the real-estate agency window.

So:

• plusieurs annonces = several listings / several ads

Celle means the one and refers back to a feminine singular noun mentioned earlier.

Here the earlier noun is:

• une annonce → feminine singular

So:

• celle = the one = the advertisement/listing

That is why French uses celle, not celui:

• celui = masculine singular
• celle = feminine singular
• ceux = masculine plural
• celles = feminine plural

In this sentence:

• plusieurs annonces introduces the general group
• celle du rez-de-chaussée singles out one specific listing from that group

French often uses demonstrative pronouns like celui / celle / ceux / celles to avoid repeating a noun.

So instead of saying:

• ...mais l’annonce du rez-de-chaussée me plaît le plus

French can say:

• ...mais celle du rez-de-chaussée me plaît le plus

This is similar to English:

• There are several listings, but the one for the ground floor appeals to me most.

Using celle sounds natural and avoids repetition.

Du rez-de-chaussée means of the ground floor or more naturally here for the ground floor / the ground-floor one.

A few parts:

• rez-de-chaussée = ground floor
• du = de + le

So literally:

• celle du rez-de-chaussée = the one of the ground floor

In natural English, that usually becomes:

• the one for the ground floor
• the ground-floor one

In context, it most likely means the listing for a ground-floor apartment or property.

Because du is the contraction of de + le.

• le rez-de-chaussée = the ground floor
• de le rez-de-chaussée becomes du rez-de-chaussée

This contraction is required in standard French.

Compare:

• de + le → du
• de + les → des
• de + la → de la
• de + l’ → de l’

So:

• celle du rez-de-chaussée = the one of/from/for the ground floor

No. This is an important vocabulary point.

In French:

• le rez-de-chaussée = ground floor
• le premier étage = first floor above the ground floor

So French follows the same numbering logic as British English:

• ground floor
• first floor
• second floor

This is different from American English, where the first floor is usually the ground level.

French has two common ways to express liking something:

• j’aime = I like / I love
• ça me plaît or cela me plaît = it pleases me / it appeals to me

In this sentence:

• celle ... me plaît le plus = that one appeals to me the most

Plaire often sounds a little more like appeal to than simple like, though in many situations both can be translated as like.

So:

• J’aime cette annonce. = I like this listing.
• Cette annonce me plaît. = This listing appeals to me / I like this listing.

Plaire works differently from aimer.

With plaire, the thing you like is the grammatical subject, and the person who likes it is an indirect object.

So:

• Cette annonce me plaît.

Literally:

• This listing pleases me.

Breakdown:

• cette annonce = subject
• me = to me
• plaît = pleases / is pleasing

This is similar to verbs like convenir à in structure.

Compare:

• J’aime cette annonce.
  = I like this listing.

• Cette annonce me plaît.
  = This listing pleases me / appeals to me.

The verb is plaire. In the present tense, third person singular is:

• il/elle plaît

The circumflex in plaît is part of the correct spelling.

Examples:

• Ce livre me plaît.
• Cette maison me plaît.

The accent does not change the basic meaning here; it is simply part of the standard written form of the verb.

Le plus means the most.

In this sentence:

• me plaît le plus = pleases me the most / I like the most

French uses le plus to form the superlative:

• plus = more
• le plus = the most

Examples:

• C’est le plus grand. = It’s the biggest.
• C’est celui qui me plaît le plus. = It’s the one I like the most.

This is the normal French order with plaire:

• indirect object pronoun + verb + superlative expression

So:

• me plaît le plus

Literally:

• pleases me the most

French does not usually say:

• me le plus plaît ✘

A useful model is:

• Cette robe me plaît.
• Cette robe me plaît plus que l’autre.
• Cette robe me plaît le plus.

Yes, that is possible, but it means something slightly different in structure.

Compare:

• ...mais celle du rez-de-chaussée me plaît le plus.
  = ...but the ground-floor one appeals to me the most.

• ...mais c’est celle du rez-de-chaussée qui me plaît le plus.
  = ...but it’s the ground-floor one that I like the most.

The original sentence is simpler and more direct. Adding qui would usually require a slightly different structure.

In context, it most likely means the listing for the ground-floor property.

Because the sentence is about annonces in an agency window, du rez-de-chaussée most naturally describes what the listing is about, not where it is physically placed.

So the likely idea is:

• there are several property listings
• the speaker prefers the one for the ground-floor apartment or unit

That said, without more context, French can sometimes leave a small ambiguity. But the real-estate reading is the most natural one here.